Radiation-induced sarcoma

Radiation-induced sarcomas can originate in either the irradiated bone or soft tissues. Most of these tumors are high-grade. The most common histologic subtypes are malignant fibrous histiocytoma (MFH) and osteosarcoma, although other histologies (eg, angiosarcoma, rhabdomyosarcoma) can occur. Tumor size and grade are the two most important prognostic factors for soft tissue sarcomas, including those associated with radiation therapy. The therapy is therefore dictated by the risk of distant metastases. High-grade tumors that are larger than 5 cm should be treated with primary chemotherapy followed by a margin-negative surgical excision of the residual disease. All low-grade tumors and high-grade tumors 5 cm or smaller should be treated with a margin-negative surgical excision, and systemic chemotherapy should be considered when a negative margin is difficult or impossible to accomplish. Radiation-induced sarcomas (either MFH or osteosarcoma) originating in bone should be approached with primary chemotherapy followed by a margin-negative excision similar to de novo bone sarcomas. The dose-intensity of the active agents should be adjusted appropriately for the age, performance status, and prior therapy in a given patient.

New agents in the treatment of soft-tissue sarcomas

The list of agents with significant activity in soft-tissue sarcomas is very short and arguably, only includes doxorubicin and ifosfamide. Several other agents such as dacarbazine, cisplatin and etoposide, to name but a few, have marginal activity and are sometimes used in combination regimes. The need for the identification of new agents with activity against this disease is therefore paramount. Soft-tissue sarcomas are very rare and diverse and as a result, new drug trials are few and far fetched. The conventionally conducted Phase II trials, which include all histologies of soft-tissue sarcomas, run the risk of an inadequate assessment of the new drug in individual subsets, which may have variable biological behaviours. On the other hand, histology-specific Phase II trials are fraught with the problems of length due to the infrequent nature of the disease and the considerable running costs. The end result is that in this era of cost-containment, soft-tissue sarcomas are not high on the priority list of many funding agencies, thus explaining the lack of any significant progress over the past two decades. Efforts at optimising the dose intensity and schedule of administration of doxorubicin and ifosfamide, have resulted in superior activity when combined and improvement in the survival of patients with high-risk localised disease. However, efforts at identifying new agents with adequate activity have not had much success. Patients, physicians and pharmaceutical industries must be encouraged to participate in multidisciplinary clinical trials in order to improve cure rates for patients with advanced disease.

A meta-analysis of the Papanicolaou smear and wet mount for the diagnosis of vaginal trichomoniasis

PURPOSE

To obtain reliable estimates of the sensitivity and specificity of the cervical Papanicolaou (Pap) smear and wet mount to diagnose vaginal trichomoniasis.

METHODS

Articles indexed in MEDLINE (1976-1998) about diagnostic tests for trichomoniasis and their listed references were retrieved. Thirty studies (9,501 patients) that used trichomonas culture as a gold standard were selected. Studies were defined as level I if they fulfilled at least two of the following three criteria: consecutive patients were evaluated prospectively, the decision to culture was not influenced by test results, and there was independent and blind comparison with culture. Studies were classified as level II if one criterion was fulfilled, and as level III otherwise.

RESULTS

The pooled sensitivity of the Pap smear for the diagnosis of trichomoniasis among level I studies was 57% (95% confidence interval [CI]: 51% to 63%) and the pooled specificity was 97% (95% CI: 93% to 100%). The likelihood ratio for a positive Pap smear was 19 among level I studies (range: 8 to 62). The pooled sensitivity of the wet mount among level I studies was 58% (95% CI: 51% to 66%); among level II studies, the sensitivity was 72% (95% CI: 62% to 81%), and among level III studies, the sensitivity was 82% (95% CI: 67% to 97%). The overall specificity of the wet mount was 99.8%.

CONCLUSIONS

A positive Pap smear for trichomonads in settings in which trichomoniasis is common (prevalence > or =20%) requires treatment. A positive Pap smear is indeterminate when the prevalence of trichomoniasis is about 10%; thus, clinicians should either confirm the diagnosis by culture or treat all such patients, recognizing that some patients will be treated unnecessarily. A culture should be obtained in women with a positive Pap smear who are unlikely to have trichomoniasis (prevalence < or =1%). While a positive wet mount is diagnostic, a negative wet mount does not exclude trichomoniasis.

Reporting and concordance of methodologic criteria between abstracts and articles in diagnostic test studies

OBJECTIVE

To evaluate the quality and concordance of methodologic criteria in abstracts versus articles regarding the diagnosis of trichomoniasis.

STUDY DESIGN

Survey of published literature.

DATA SOURCES

Studies indexed in MEDLINE (1976-1998).

STUDY SELECTION

Studies that used culture as the gold or reference standard.

DATA EXTRACTION

Data from abstract and articles were independently abstracted using 4 methodologic criteria: (1) prospective evaluation of consecutive patients; (2) test results did not influence the decision to do gold standard; (3) independent and blind comparison with gold standard; and (4) broad spectrum of patients used. The total number of criteria met for each report was calculated to create a quality score (0-4).

MEASUREMENTS AND MAIN RESULTS

None of the 33 abstracts or full articles reported all 4 criteria. Three criteria were reported in none of the abstracts and in 18% of articles (95% confidence interval [95% CI] 8.6% to 34%). Two criteria were reported in 18% of abstracts (95% CI, 8.6% to 34%) and 42% of articles (95% CI, 27% to 59%). One criterion was reported in 42% of abstracts (95% CI, 27% to 59%) and 27% of articles (95% CI, 15% to 44%). No criteria were reported in 13 (39%) of 33 abstracts (95% CI, 25% to 56%) and 4 (12%) of 33 articles (95% CI, 4.8% to 27%). The agreement of the criteria between the abstract and the article was poor (kappa -0.09; 95% CI, -0.18 to 0) to moderate (kappa 0.53; 95% CI, 0.22 to 0.83).

CONCLUSIONS

Information on methods basic to study validity is often absent from both abstract and paper. The concordance of such criteria between the abstract and article needs to improve.

Multiple cadherin superfamily members with unique expression profiles are produced in rat testis

Adhesion between germ and Sertoli cells is thought to be crucial for spermatogenesis. Cadherin superfamily proteins, including classic cadherins and protocadherins, are important mediators of cell-cell adhesion. Using a degenerate PCR cloning strategy, we surveyed the expression of cadherin superfamily members in rat testis. Similar to brain, testis expressed a large number of cadherin superfamily members: 7 classic cadherins of both types I and II, 14 protocadherins, 2 protocadherin-related cadherins, and 1 cadherin-related receptorlike protein. All three protocadherin families (alpha, beta, and gamma) were found in testis. Using a semiquantitative RT-PCR assay, messenger RNA expression was determined for each cadherin superfamily member during a postnatal developmental time-course and following ablation of specific testis cell types by ethanedimethanesulfonate, methoxyacetic acid, and 2,5-hexanedione. Diverse expression patterns were observed among the cadherins, suggesting that cadherin expression is cell type-specific in testis. The large number and variety of cadherin superfamily members found in testis supports a critical function for cadherin-mediated cell-cell adhesion in spermatogenesis.

Systematic review of diagnostic tests for vaginal trichomoniasis

OBJECTIVE

To review critically and to summarize the evidence of diagnostic tests and culture media for the diagnosis of Trichomonas vaginitis.

METHODS

We performed a systematic review of literature indexed in MEDLINE of studies that used Trichomonas culture as the reference standard (9,882 patients, 35 studies). Level I studies (5,047 patients, 13 studies) fulfilled at least two of three criteria: 1) consecutive patients were evaluated prospectively, 2) decision to culture was not influenced by test results, and 3) there was independent and blind comparison to culture.

RESULTS

The sensitivity of the polymerase chain reaction technique (PCR) was 95% (95% CI 91% to 99%), and the specificity was 98% (95% CI 96% to 100%). One study was classified as Level I evidence (52 patients). The sensitivity of the enzyme-linked immunosorbent assay was 82% (95% CI 74% to 90%), and the specificity was 73% (95% CI 35% to 100%). The sensitivity of the direct fluorescence antibody was 85% (95% CI 79% to 90%), and the specificity was 99% (95% CI 98% to 100%). Sensitivities of culture media were 95% for Diamond's, 96% for Hollander, and 95% for CPLM.

CONCLUSIONS

The sensitivity and specificity of tests to diagnose trichomoniasis vary widely.

Focal angiogen therapy using intramyocardial delivery of an adenovirus vector coding for vascular endothelial growth factor 121

BACKGROUND

Adenovirus (Ad) vector-mediated gene therapy strategies have emerged as promising modalities for the "biological revascularization" of tissues. We hypothesized that direct intramyocardial, as opposed to intracoronary, administration of an Ad vector coding for the vascular endothelial growth factor 121 cDNA (Ad(GV)VEGF121.10) would provide highly focal Ad genome levels, and increases in VEGF, ideal for inducing localized therapeutic angiogenesis.

METHODS

Persistence and regional distribution of the vector were assessed by TaqMan real-time quantitative polymerase chain reaction technology and enzyme-linked immunosorbent assay, after intramyocardial Ad(GV)VEGF121.10 in the rat, and either intramyocardial or intracoronary (circumflex territory) vector in Yorkshire swine. Based on these results, we assessed the focal nature of the improved cardiac blood flow in a previously reported porcine myocardial ischemia model.

RESULTS

Intramyocardial delivery of Ad(GV)VEGF121.10 in the rat resulted in local persistence of the Ad genome that decreased 1,000-fold over 3 weeks, with peak myocardial VEGF expression 24 to 72 h after vector delivery. After intramyocardial Ad(GV)VEGF121.10 in the circumflex distribution of pigs, Ad vector genome and VEGF protein levels were more than 1,000-fold and more than 90-fold higher, respectively, in this distribution than in other myocardial regions. In comparison, intracoronary injection yielded maximum myocardial Ad genome and VEGF levels 33-fold and 9-fold lower, respectively, than that after intramyocardial delivery. Angiograms obtained 28 days after intramyocardial Ad(GV)VEGF121.10 demonstrated rapid circumflex reconstitution via collaterals localized to the region of vector administration.

CONCLUSIONS

These studies demonstrate that direct intramyocardial administration of Ad(GV)VEGF121.10 results in focal genome and VEGF levels, including focal angiogenesis, sufficient to normalize blood flow to the ischemic myocardium, findings that are relevant to designing human trials of gene therapy-mediated cardiac angiogenesis.

Waiting for microbiologic data to direct therapy against nosocomial infections in febrile surgical patients: are outcomes worsened?

HYPOTHESIS

Allowing adequate time for laboratory and culture results before initial treatment may be associated with a worse outcome in nosocomial infections.

DESIGN

Cohort study of all episodes of nosocomial infection from December 10, 1996, to October 28, 1998.

SETTING

Surgical services at a university hospital.

PATIENTS AND METHODS

In surgical patients presenting with fever, 372 episodes of nosocomial infection were evaluated. Nosocomial infections were divided by time from fever to intervention (< or =12, 13-24, and >24 hours). These groups were subdivided by Acute Physiology and Chronic Health Evaluation II (APACHE II) scores into low (< or =10 [n = 114]), moderate (11-20 [n = 169]), and high severity of illness (>20 [n = 89]). Pneumonia and bloodstream infections were divided by APACHE II scores into low (< or =15 [n = 55 and n = 56, respectively]) or high severity of illness (>15 [n = 84 and n = 77, respectively]).

MAIN OUTCOME MEASURES

Mortality, length of stay.

RESULTS

No difference in outcome was seen between different time intervals from fever to intervention for nosocomial infections in patients with APACHE II scores of no more than 10. Patients treated more than 24 hours after fever were significantly younger than those treated at no more than 12 and 13 to 24 hours with APACHE II scores of 11 to 20 (P<.05) and more than 20 (P<.05). Mortality and length of stay for patients treated at later time intervals were comparable with those of patients treated earlier with similar APACHE II scores. There was no difference in outcome for patients with pneumonia or bloodstream infection.

CONCLUSIONS

Episodes of infection in which treatment was withheld until initial microbiologic data were available (24 hours) did not have worse outcomes compared with those treated earlier. Waiting for laboratory and culture results to direct antibiotic therapy for nosocomial infections does not appear harmful and may be potentially beneficial.

The synthesis and biological evaluation of non-peptidic matrix metalloproteinase inhibitors

Novel sulfonamide matrix metalloproteinase inhibitors of general formula (9) were synthesised by a route involving a stereoselective conjugate addition reaction. Enzyme selectivity was found to be dependant on the nature of the sulfonamide substituents. Compounds (9f, 9q) are potent selective collagenase inhibitors with good oral bioavailability.

Six-month assessment of a phase I trial of angiogenic gene therapy for the treatment of coronary artery disease using direct intramyocardial administration of an adenovirus vector expressing the VEGF121 cDNA

OBJECTIVE

To summarize the 6-month follow-up of a cohort of patients with clinically significant coronary artery disease who received direct myocardial injection of an E1-E3- adenovirus (Ad) gene transfer vector (Ad(GV)VEGF121.10) expressing the human vascular endothelial growth factor (VEGF) 121 cDNA to induce therapeutic angiogenesis.

BACKGROUND

Therapeutic angiogenesis describes a novel approach to the treatment of vascular occlusive disease that uses the administration of growth factors known to induce neovascularization of ischemic tissues.

METHODS

Direct myocardial injection of Ad(GV)VEGF121.10 into an area of reversible ischemia was carried out in 21 patients as an adjunct to conventional coronary artery bypass grafting (group A, n = 15) or as sole therapy using a minithoracotomy (group B, n = 6).

RESULTS

No evidence of systemic or cardiac-related adverse events related to vector administration was observed up to 6 months after therapy. Trends toward improvement in angina class and exercise treadmill testing at 6-month follow-up in the sole therapy group suggest the effects of this therapy are persistent for > or =6 months.

CONCLUSIONS

This study suggests that direct myocardial administration of Ad(GV)VEGF121.10 appears to be well tolerated in patients with clinically significant coronary artery disease. Initiation of phase II evaluation of this therapy appears warranted.

Long-term outcome of patients with American Joint Committee on Cancer stage IIB extremity soft tissue sarcomas

PURPOSE

It has been suggested that patients with small (< 5 cm), high-grade extremity soft tissue sarcomas (STS) have an excellent overall prognosis and, consequently, may not require adjuvant therapies.

PATIENTS AND METHODS

A comprehensive review of all patients with extremity STS treated at a tertiary care cancer hospital over a 9-year period (January 1984 to December 1992) was performed. Prognostic factors, treatment data, and long-term outcome were evaluated in the subset of 111 patients with American Joint Committee on Cancer stage IIB (G3/4, T1a/b) disease.

RESULTS

The median tumor size was 3.0 cm (range, 0.6 to 4.9 cm), and 55 tumors (50%) were deep in location. All patients underwent surgical resection; 68 (61%) received pre- or postoperative radiotherapy, and 32 (29%) received doxorubicin-based chemotherapy. The median follow-up was 76 months. Forty patients (36%) experienced 59 recurrences. First recurrences occurred at local, regional, and distant sites in 21, five, and 14 patients, respectively. The 5-year actuarial local recurrence-free, distant recurrence-free, disease-free, and overall survival rates were 82%, 83%, 68%, and 83%, respectively. The presence of a microscopically positive surgical margin was an independent adverse prognostic factor for both local recurrence (relative risk [RR] = 3.75; 95% confidence interval [CI], 1.25 to 11.25; P =.02) and disease-free survival (RR = 2.57; 95% CI, 1.33 to 4.98; P =.005).

CONCLUSION

Event-free outcome for this subset of patients with high-grade STS does not seem as favorable as previously reported by other investigators. Patients who undergo maximal surgical resection with microscopically positive margins represent a subset of T1 STS patients who warrant consideration for adjuvant therapies.

Angiogenesis gene therapy: phase I assessment of direct intramyocardial administration of an adenovirus vector expressing VEGF121 cDNA to individuals with clinically significant severe coronary artery disease

BACKGROUND

Therapeutic angiogenesis, a new experimental strategy for the treatment of vascular insufficiency, uses the administration of mediators known to induce vascular development in embryogenesis to induce neovascularization of ischemic adult tissues. This report summarizes a phase I clinical experience with a gene-therapy strategy that used an E1(-)E3(-) adenovirus (Ad) gene-transfer vector expressing human vascular endothelial growth factor (VEGF) 121 cDNA (Ad(GV)VEGF121.10) to induce therapeutic angiogenesis in the myocardium of individuals with clinically significant coronary artery disease.

METHODS AND RESULTS

Ad(GV)VEGF121.10 was administered to 21 individuals by direct myocardial injection into an area of reversible ischemia either as an adjunct to conventional coronary artery bypass grafting (group A, n=15) or as sole therapy via a minithoracotomy (group B, n=6). There was no evidence of systemic or cardiac-related adverse events related to vector administration. In both groups, coronary angiography and stress sestamibi scan assessment of wall motion 30 days after therapy suggested improvement in the area of vector administration. All patients reported improvement in angina class after therapy. In group B, in which gene transfer was the only therapy, treadmill exercise assessment suggested improvement in most individuals.

CONCLUSIONS

The data are consistent with the concept that direct myocardial administration of Ad(GV)VEGF121.10 to individuals with clinically significant coronary artery disease appears to be well tolerated, and initiation of phase II evaluation of this therapy is warranted.

New chemotherapeutic strategies for soft tissue sarcomas

Advanced soft-tissue sarcomas are still incurable in the vast majority of patients. The currently available standard methods of treatment such as surgery, radiation therapy, and chemotherapy have a very modest impact on the natural history of advanced soft tissue sarcomas. Nevertheless, until new strategies become widely available and applicable to this disease, we are obligated to optimize the current resources and make the best use of these modalities. We discuss the approaches of standard chemotherapy used in a dose-intensive fashion (especially in high-risk patients at an earlier stage), attempts to find new drugs with activity in this disease, and tests of the concepts of anti-angiogenic and differentiation therapy. To improve cure rates, patients and physicians must be encouraged to participate in multidisciplinary clinical trials.

Exogenous control of cardiac gene therapy: evidence of regulated myocardial transgene expression after adenovirus and adeno-associated virus transfer of expression cassettes containing corticosteroid response element promoters

OBJECTIVE

Because of the relative inaccessibility of the heart for repeated gene therapy, it would be useful to regulate the expression of transgenes delivered in a single dose of a gene therapy vector. Incorporation into the vector of a regulatable promoter that is responsive to pharmacologic agents that are widely used and well tolerated in clinical practice represents such a control strategy.

METHODS

A replication-deficient adenovirus or an adeno-associated virus containing a chimeric promoter composed of 5 glucocorticoid response elements and the murine thrombopoietin complementary DNA (AdGRE.mTPO or AAVGRE.mTPO) was administered to the hearts of Sprague-Dawley rats. Platelet levels were evaluated as a reporter of transgene activity with or without dexamethasone. For comparison, rats received a control adenovirus vector, AdCMV.mTPO or AdCMV.Null, and the control adeno-associated virus vector AAVCMV.luc, which encodes for the firefly luciferase (luc) gene.

RESULTS

Platelet elevation in the AdGRE.mTPO group peaked 4 days after dexamethasone administration, with a return to baseline 1 week after the initial corticosteroid dose. Subsequent dexamethasone administration at 2 and 4 weeks resulted in similar but progressively decreased responses. The AAVGRE.mTPO group had 5 peak platelet levels to a minimum of 2.2-fold with respect to baseline without diminution with subsequent dexamethasone administrations out to 169 days. In contrast, the AdCMV.Null and AAVCMV.luc groups demonstrated no increase in platelet counts and the AdCMV.mTPO group demonstrated a slow rise to a single peak platelet count independent of dexamethasone administration.

CONCLUSION

It may be possible to control on demand the expression of a gene transferred to the heart. This strategy should be useful in cardiac gene therapy.

New phosphate binding agents: ferric compounds

Several prior studies suggest that ferric compounds bind dietary phosphate and possess clinical potential as phosphate binding agents. Therefore, this study was conducted to measure the effect of several ferric compounds on intestinal phosphate binding and absorption. Balance studies lasting 2 to 4 wk were performed in normal and azotemic (achieved by subtotal nephrectomy) rats maintained on a 1.02% phosphorus diet supplemented with ferric salts (formulated to 0.95% Fe) or no ferric salt (control). In rats with normal renal function (average creatinine clearance, 4.0 ml/min per kg), the average net intestinal absorption of phosphate over all balance periods was 103.3 mg/d for the control group versus 84.7 mg/d for the ferric citrate group (P < 0.005). In the azotemic rats (average creatinine clearance, 3.3 ml/min per kg), the average net intestinal absorption of phosphate over all balance periods was significantly lower for the three ferric groups than the control groups (P < or = 0.02): 95.3 mg/d for the control group versus 75.6 mg/d for the ferric ammonium citrate-treated group (P = 0.058), 77.0 mg/d for the ferric citrate-treated group (P = 0.057), and 62.5 mg/d for the ferric chloride-treated group (P < 0.002). Urinary phosphate excretion fell, sometimes to an even greater extent than did intestinal absorption, yielding no net reduction in phosphate balance in these growing, young animals with relatively preserved renal function. Calcium balance was largely unaffected by the ferric compounds. There were trends toward decreased serum phosphorus and parathyroid hormone concentrations and increased iron and hematocrit in the ferric-treated azotemic groups. All tested ferric compounds were well tolerated, but animal growth was stunted in the ferric chloride animals compared with the control group. Phosphate binding was estimated at 85 to 180 mg per gram of elemental iron, which is comparable to other phosphate binding agents. Ferric salts decrease net intestinal phosphate absorption and hold promise for the treatment of phosphate retention in patients with renal failure.

Safety of direct myocardial administration of an adenovirus vector encoding vascular endothelial growth factor 121

A gene therapy strategy involving direct myocardial administration of an adenovirus (Ad) vector encoding the vascular endothelial growth factor 121 cDNA (Ad(GV)VEGF121.10) has been shown to be capable of "biological revascularization" of ischemic myocardium in an established porcine model [Mack, C.A. (1998). J. Thorac. Cardiovasc. Surg. 115, 168-177]. The present study evaluates the local and systemic safety of this therapy in this porcine ischemia model and in normal mice. Myocardial ischemia was induced in Yorkshire swine with an ameroid constrictor 21 days prior to vector administration. Ad(GV)VEGF121.10 (10(9) or 10(10) PFU), Ad5 wild type (10(9) PFU), AdNull (control vector with no transgene; 10(9) PFU), saline, or no injection (naive) was administered in 10 sites in the ischemic, circumflex distribution of the myocardium. Toxicity was assessed by survival, serial echocardiography, blood analyses, and myocardial and liver histology at 3 and 28 days after vector administration. All pigs survived to sacrifice, except for one animal in the Ad(GV)VEGF121.10 (10(10) PFU) group, which died as a result of oversedation. Echocardiograms of Ad(GV)VEGF121.10-treated pigs demonstrated no differences in pericardial effusion, mitral valve regurgitation, or regional wall motion compared with control pigs. Intramyocardial administration of Ad(GV)VEGF121.10 included only minimal myocardial inflammation and necrosis, and no hepatic inflammation or necrosis. Only a mild elevation of the white blood cell count was encountered on day 3, which was transient and self-limited in the Ad(GV)VEGF121.10 group as compared with the saline-treated animals. As a measure of inadvertent intravascular administration of vector, normal C57/BL6 mice received intravenous Ad(GV)VEGF121.10 (10(4), 10(6), 5 x 10(7), or 10(9) PFU), AdNull (5 x 10(7) or 10(9) PFU), or saline. Toxicity was assessed by survival, blood analyses, and organ histology at 3 and 7 days after vector administration. A separate group of C57/BL6 mice received intravenous AdmVEGF164 (Ad vector encoding the murine VEGF164 cDNA), Ad(GV)VEGF121.10, AdNull (10(8) PFU each group), or saline to assess duration of expression and safety of a homologous transgene. All mice survived to sacrifice except for 40% of the mice in the highest (10(9) PFU; a dose more than 10(3)-fold higher by body weight than the efficacious dose in pigs) Ad(GV)VEGF121.10 dose group, which died on days 5-6 after vector administration. The only differences seen in the blood analyses between treated and control mice were in the very high Ad(GV)VEGF121.10 dose group (10(9) PFU), which demonstrated an anemia as well as an increase in alkaline phosphatase when compared with all other treatment groups. Hepatic VEGF levels by ELISA in AdmVEGF164-treated mice did not persist beyond 14 days after vector administration, suggesting that persistent expression of a homologous VEGF gene transferred with an Ad vector is not a significant safety risk. Although this is not a chronic toxicity study, these data demonstrate the safety of direct myocardial administration of Ad(GV)VEGF121.10, and support the potential use of this strategy to treat human myocardial ischemia.

Phytochrome D acts in the shade-avoidance syndrome in Arabidopsis by controlling elongation growth and flowering time

Shade avoidance in higher plants is regulated by the action of multiple phytochrome (phy) species that detect changes in the red/far-red ratio (R/FR) of incident light and initiate a redirection of growth and an acceleration of flowering. The phyB mutant of Arabidopsis is constitutively elongated and early flowering and displays attenuated responses to both reduced R/FR and end-of-day far-red light, conditions that induce strong shade-avoidance reactions in wild-type plants. This indicates that phyB plays an important role in the control of shade avoidance. In Arabidopsis phyB and phyD are the products of a recently duplicated gene and share approximately 80% identity. We investigated the role played by phyD in shade avoidance by analyzing the responses of phyD-deficient mutants. Compared with the monogenic phyB mutant, the phyB-phyD double mutant flowers early and has a smaller leaf area, phenotypes that are characteristic of shade avoidance. Furthermore, compared with the monogenic phyB mutant, the phyB-phyD double mutant shows a more attenuated response to a reduced R/FR for these responses. Compared with the phyA-phyB double mutant, the phyA-phyB-phyD triple mutant has elongated petioles and displays an enhanced elongation of internodes in response to end-of-day far-red light. These characteristics indicate that phyD acts in the shade-avoidance syndrome by controlling flowering time and leaf area and that phyC and/or phyE also play a role.

Therapeutic angiogenesis: protein and gene therapy delivery strategies

Angioplasty and surgical bypass, the primary interventional therapies for the treatment of atherosclerosis, are limited by the development over time of native vessel restenoses and graft occlusions. Furthermore, these therapies are not options for a significant number of individuals in whom the extent of vascular pathology is especially severe or widespread. Angiogenesis, the growth of new vasculature, is a critical biological response to ischemia that provides collateralization, or 'biological revascularization' of vascular obstructions. Therapeutic angiogenesis is a strategy whereby one of several known 'angiogens', mediators that induce angiogenesis, can be administered to augment the native angiogenic processes and enhance the formation of collateral vasculature. This report describes the techniques available for providing therapeutic angiogenesis, including acute and sustained-release techniques to deliver protein angiogens and a number of gene therapy strategies to deliver genes coding for the angiogens.

The c-wave of the electroretinogram recorded under clinical conditions from rabbits

To determine whether large and repeatable c-waves can be recorded from rabbits with equipment already in use in clinical electroretinographic laboratories, the Burian-Allen electrode, connected bipolarly or monopolarly, was used to record electroretinograms from pigmented rabbits. The Jet electrode was also used. The c-waves elicited by long-duration (4-second) stimuli were compared to those elicited by stroboscopic stimuli. In addition, the c-waves recorded with direct-coupled amplification were compared to those recorded with condenser-coupled amplification (one-half-amplitude bandpass=0.1 Hz). The b-wave amplitude was not altered by the amplifier coupling or by the two stimulus durations. The largest c-waves were elicited by 4-second-duration stimuli and recorded with direct-coupled amplification. Although the c-wave amplitude was reduced by stroboscopic stimuli and by condenser coupling, large and repeatable c-waves were elicited by stroboscopic stimuli and recorded with condenser-coupled amplification. A comparison of stimulus duration and amplifier coupling showed that the stimulus duration was more important in recording large-amplitude c-waves. Similar results were obtained with the Jet electrode. We conclude that repeatable and large c-waves can be elicited by a stroboscopic stimuli and can be recorded with condenser-coupled amplification with good low-frequency response from rabbits.

Surgical gowns and drapes into the 21st century

According to the MDD (Medical Devices Directive) 93/42/EEC of 13 June 1993, medical products including gowns and drapes must provide a high level of protection for patients, users and others. The European Commission CEN/TC 205/WG 14, under the leadership of its convenor, Professor Werner, is developing a mandatory European standard on the basic requirements and test methods for disposable and reusable materials for protection of patients, surgical personnel, and operating room facilities i.e. gowns and drapes. This European standard is intended to clarify the situation with respect to products and their properties, defining basic requirements, for users and manufacturers of medical products. Future use of standard cotton textiles and conventional cotton-polyester mixed textiles is uncertain as they may not meet the requirements of the new standard, i.e. resistance to penetration by microbiological microorganisms, liquids and particle release. However, there are innovative reusable barrier surgical drapes and gowns which meet the basic requirements of the standard made from liquid repellent micro-filament materials, material laminates and perhaps some specific cotton polyester materials which have been chemically modified. In the new standard based on CEN/TC 205/WG 14, quality assurance for reprocessing of surgical gowns and drapes is critical. The manufacturer/distributor must use validated processes to prove that the requirements of this European Standard are met. Quality Assurance Systems will be required to give proof of decontamination, disinfection and sterilisation. Specified processes are to be used to maintain the properties of the materials throughout reprocessing. It is the responsibility of the hospital to assure optimal protection of patients and users. In case of a lawsuit, this could lead to the burden of proof being shifted to the hospital, with related risk of liability because it is always assumed that the work is being done according to the 'state of the art'. Difficult situations arise when it must be proved that one has acted equivalent to or better than the standard procedures and that no mistakes are made. Because of this risk of liability alone, the question of what surgical materials are used in the future should be considered very carefully.

Phase II study of CI-980 (NSC 635370) in patients with previously treated advanced soft-tissue sarcomas

Doxorubicin and ifosfamide are the two most active agents in the treatment of soft-tissue sarcomas. Patients whose tumors have failed these two drugs have very limited systemic therapy options. It is, therefore, important to identify newer drugs with activity against this disease. CI-980 is a synthetic mitotic inhibitor that binds to tubulin at the colchicine binding site and inhibits the polymerization of tubulin and blocks cell cycle progression in mitosis. Given its broad spectrum activity against several solid tumor models in vivo, we decided to perform a phase 2 study of this drug in previously treated soft-tissue sarcomas. A total of 18 eligible and evaluable patients were entered in the first stage of the trial. The median age was 53 yrs (range, 17-72). No objective responses have been noted. Six patients had stable disease after a median of 3.5 cycles of chemotherapy while 12 others had progressive disease. A total of 48 cycles were administered, 42 of which were administered at dose level 0 (4.5 mg/m2/d x 3). The median AGC nadir was 1.2/microl(0.1 -4.7) on day 10 and the median platelet nadir was 150,000/microl (31,000-338,000). Twenty cycles were complicated with grade 3-4 neutropenia and two cycles were complicated with FUO. There were no CNS toxicities. One patient had a grade 1 thrombophlebitis in 2 cycles and one other patient had a grade 4 thrombophlebitis in one cycle. In conclusion, CI-980 was well tolerated at this dose and schedule but inactive in soft-tissue sarcomas.

The surgical gowns and drapes of tomorrow. Specifying material performance and test methods

A mandatory European standard is being developed to establish basic requirements and test methods for disposable and reusable materials used for surgical gowns and drapes. Once this standard has been adopted, the continued use of cotton textiles and conventional cotton-polyester-mixed textiles will become questionable. This article outlines the proposed requirements and looks at alternative methods that use liquid-repellent micro-filament textiles or liquid-proof textile laminates.