A multicenter, randomized phase 2 study to establish combinations of CBP501, cisplatin and nivolumab for ≥3rd-line treatment of patients with advanced pancreatic adenocarcinoma

BACKGROUND

There is no standard of care for ≥ 3rd-line treatment of metastatic pancreatic adenocarcinoma (PDAC). CBP501 is a novel calmodulin-binding peptide that has been shown to enhance the influx of platinum agents into tumor cells and tumor immunogenicity. This study aimed to (1) confirm efficacy of CBP501/cisplatin/nivolumab for metastatic PDAC observed in a previous phase 1 study, (2) identify combinations that yield 35% 3-month progression-free survival rate (3MPFS) and (3) define the contribution of CBP501 to the effects of combination therapy.

METHODS

CBP501 16 or 25 mg/m2 (CBP(16) or CBP(25)) was combined with 60 mg/m2 cisplatin (CDDP) and 240 mg nivolumab (nivo), administered at 3-week intervals. Patients were randomized 1:1:1:1 to (1) CBP(25)/CDDP/nivo, (2) CBP(16)/CDDP/nivo, (3) CBP(25)/CDDP and (4) CDDP/nivo, with randomization stratified by ECOG PS and liver metastases. A Fleming two-stage design was used, yielding a one-sided type I error rate of 2.5% and 80% power when the true 3MPFS is 35%.

RESULTS

Among 36 patients, 3MPFS was 44.4% in arms 1 and 2, 11.1% in arm 3% and 33.3% in arm 4. Two patients achieved a partial response in arm 1 (ORR 22.2%; none in other arms). Median PFS and OS were 2.4, 2.1, 1.5 and 1.5 months and 6.3, 5.3, 3.7 and 4.9 months, respectively. Overall, all treatment combinations were well tolerated. Most treatment-related adverse events were grade 1-2.

CONCLUSIONS

The combination CBP(25)/(16)/CDDP/nivo demonstrated promising signs of efficacy and a manageable safety profile for the treatment of advanced PDAC.

CLINICAL TRIAL REGISTRATION

NCT04953962.

In vitroassessment of the efficacy of thermal therapy in human benign prostatic hyperplasia

The successful management of BPH with minimally invasive thermal therapies requires a firm understanding of the temperature-time relationship for tissue destruction. In order to accomplish this objective, the present in vitro study assesses the cellular viability of human BPH tissue subjected to an experimental matrix of different temperature-time combinations. Hyperplastic prostate tissue was obtained from 10 radical prostatectomy specimens resected for adenocarcinoma. A portion of hyperplastic tissue from the lateral lobe of each prostate was sectioned into multiple 1 mm thick tissue strips, placed on a coverslip and thermally treated on a controlled temperature copper block with various temperatures (45-70 degrees C) for various times (1-60 min). After heat treatment, the tissue slices were cultured for 72 h and viability was assessed using two independent assays: histology and dye uptake for stromal tissue and using histology alone for the glandular tissue. The hyperplastic human prostate tissue showed a progressive histological increase in irreversible injury with increasing temperature-time severity. The dye uptake and histology results for stromal viability were similar for all temperature-time combinations. In vitro thermal injury showed 85-90% stromal destruction (raw data) of human BPH for temperature-time combinations of 45 degrees C for 60 min, 50 degrees C for 30 min, 55 degrees C for 5 min, 60 degrees C for 2 min and 70 degrees C for 1 min. Apoptosis was also identified in the control and milder treated tissues with the degree of glandular apoptosis (about 20%) more than that seen in the stromal regions (< 5%). The Arrhenius model of injury was fitted to the data for conditions leading to a 90% drop in viability (normalized to control) obtained for stromal tissue. The activation energies (E) were 40.1 and 38.4 kcal/mole for the dye uptake study and histology, respectively, and the corresponding frequency factors (A) were 1.1 x 10(24) and 7.78 x 10(22)/s. This study presents the first temperature-time versus tissue destruction relation for human BPH tissue. Moreover, it supports the concept that higher temperatures can be used for shorter durations to induce tissue injury comparable with the current clinically recommended lower temperature-longer time treatments (i.e. 45 degrees C for 60 min) for transurethral microwave thermotherapy of the prostate.

Pre-Clinical Evaluation of Direct Current Ablation for the Treatment of Benign Prostatic Hyperplasia

Benign Prostatic Hyperplasia (BPH) is a non-cancerous growth of the prostate gland affecting about 50% of the men over age 50. As men age, the prostate continues to grow leading to increased prostate volume, which may cause lower urinary tract symptoms (LUTS). These symptoms can include the inability to completely empty the bladder, urine retention, and a profound sensation of urgency. Direct Current (DC) ablation may be applied to treat these symptoms as a minimally-invasive alternative to surgery, medication, or thermal ablation, by causing tissue necrosis within the lateral lobes of the prostate. The objective of this study was to evaluate the effects of DC ablation in canine prostates by investigating how the resulting necrosis would change the macrostructure of the prostate for the potential treatment of symptomatic BPH. DC ablation is achieved by passing direct current through two electrodes in tissue, causing the formation of hydrogen ions at the anode and hydroxyl ions at the cathode. These ions diffuse through the tissue causing a pH of ∼1 at the anode, and ∼13 at the cathode. The extreme anti-physiological pH regions cause cellular necrosis and form in a predictable manner that is directly proportional to the charge delivered. The controlled shape and size of the lesions allow for predictable necrotic zones and enable treatment optimization. Treatment was performed on 6 acute and 8 chronic canine subject by performing a laparotomy and inserting electrodes through the prostate capsule. Acute subjects were sacrificed before recovery, while chronic subjects were sacrificed after 1, 3, 20, 40, and 60 days to investigate the healing cascade of the prostate after treatment. The chronic subjects were monitored for changes in urination or defecation patterns. Urine and blood samples were collected to evaluate the subjects' health throughout the study. Both macro-visual and pathological analyses were done to evaluate tissue response all acute and chronic subjects. Cellular necrosis within the prostate was significant and exhibited a dose response within the range of 0.07 to 0.10 cm3/coulomb for each electrode pair. The does response is defined as the ratio of necrotic tissue created, to charge delivered. Necrotic prostate cells resulted in voids with minimal scar tissue and a visible reduction in prostate mass. The treatment followed tissue planes constraining necrotic zones to the region between the prostate capsule and prostatic urethra. Both normal and hyperplastic tissues were treated and exhibited necrosis. No necrosis was observed outside the prostate. DC ablation has been demonstrated to create well-defined, predictable, and repeatable regions of cellular necrosis and structural changes in canine prostates. This technology may offer promise for the treatment of symptomatic BPH with an appropriately designed delivery system. Other potential applications include other benign and malignant tumors within the body.

Detection of Changes in Alveolar Macrophage Iron Status Induced by Select PM2.5-Associated Components Using Iron-Response Protein Binding Activity

The extent of adverse health effects, including induction/exacerbation of infectious lung disease, arising from entrainment of equivalent amounts (or exposure to a fixed increment) of fine particulate matter (PM2.5) can vary from region to region or city to city in a region. To begin to explain how differing effects on host resistance might arise after exposure to PM2.5 from various sites, we hypothesized that select metals (e.g., V, Al, and Mn) in each PM2.5 caused changes in alveolar macrophage (AM) Fe status that, ultimately, would lead to altered antibacterial function. To test this, iron-response protein (IRP) binding activity in a rat AM cell line was assessed after exposure to Fe alone and in conjunction with V, Mn, and/or Al at ratios of V:Fe, Al:Fe, or Mn:Fe encountered in PM2.5 samples from New York City, Los Angeles, and Seattle. Results indicated that V and Al each significantly altered IRP activity, though effects were not consistently ratio-(i.e., dose-) dependent; Mn had little impact on activity. We conclude that the reductions in Fe status detected here via the IRP assay arose, in part, from effects on transferrin-mediated Fe3+ delivery to the AM. Ongoing studies using this assay are allowing us to better determine: (1) whether mass (and/or molar) relationships between Fe and V, Al, and/or Mn in any PM2.5 sample consistently govern the extent of change in AM Fe status; (2) how much any specified PM2.5 constituent (metal or nonmetal) contributes to the overall disruption of Fe status found induced by an intact parent sample; and (3) whether induced changes in binding activity are relatable to other changes expected to occur in the AM, that is, in IRP-dependent mRNA/levels of ferritin/transferrin receptor and Fe-dependent functions. These studies demonstrate that pollutant-induced effects on lung cell Fe status can be assessed in a reproducible manner using an assay that can be readily performed by investigators who might otherwise have no access to other very costly analytical equipment, such as graphite atomic absorption or x-ray fluorescence spectro(photo)meters.

Efficacy and safety of axitinib (AG-013736; AG) in patients (pts) with advanced non-small cell lung cancer (NSCLC): A phase II trial

7507

Background: A correlation between vascular endothelial growth factor (VEGF), microvessel density, and prognosis has been reported in pts with NSCLC. AG is a small molecule inhibitor of the receptor tyrosine kinases, with picomolar potency against VEGFR 1, 2 and 3 and nanomolar potency against PDGFR-β and KIT. This is an open-label, multicenter phase II study examining the efficacy and safety of AG in pts with advanced NSCLC. Methods: Pts with stage IIIB or metastatic NSCLC received AG 5 mg BID. Eligibility criteria included measurable disease and ECOG performance status of 0 or 1. A Simon 2-stage minimax design was used with 18 pts in the first stage plus an additional 14 in the second stage if 1/18 pts responded. The primary endpoint was response rate (RR) according to RECIST. Results: A total of 32 pts were enrolled: median age was 66 yrs (39–80); histologies were adenocarcinoma (75%), squamous cell carcinoma (9%), and not otherwise specified (16%); 56% male/44% female; 72% received prior chemotherapy, 47% prior surgery, 47% prior radiotherapy, 9% investigational therapy, 3% immunotherapy, and 13% were treatment-naïve. Mean duration of treatment was 93 days (1–271). Three (9.4%) investigator confirmed responses were reported with a 95% confidence interval (CI) of 2, 25. Median duration of response was 9.4 months (mo). Median survival was 12.8 mo (95% CI: 9.9 mo, undefined) and progression-free survival was 5.8 mo (95% CI: 3.8 mo, 10.2 mo). 26 (81%) pts discontinued treatment: lack of efficacy 19 pts (59%), adverse events 5 pts (16%), death 1 pt (3%), and withdrawal of consent 1 pt (3%). Grade 3/4 toxicities (=5%) were fatigue (22%), diarrhea (6%), hypertension (6%) and hyponatremia (6%). Conclusions: AG demonstrates single- agent activity in pts with advanced NSCLC. Therapy is well tolerated with manageable toxicity in this population. Further investigation in this setting is warranted.

[Table: see text]

Transdermal testosterone in female cancer survivors with decreased libido

8507

Background: Problems with sexual functioning are an issue negatively affecting the quality of life of female cancer survivors. Testosterone has been implicated as an important hormone in sexual functioning such as libido. Studies of transdermal testosterone have shown benefit in enhancing libido in women who have been diagnosed with hypoactive sexual desire disorder after bilateral oophorectomy. This phase III placebo-controlled clinical trial evaluated whether transdermal testosterone would increase libido in female cancer survivors. Methods: Women with a history of cancer, currently without evidence of disease, were eligible if they reported a decrease in sexual desire and had a sexual partner. Women must have been postmenopausal. Eligible women were randomized to receive 2% testosterone in Vanicream (10 mg daily) versus placebo Vanicream for four weeks, then crossed over to the opposite treatment. The primary endpoint, libido, was measured via the desire subscales of the Changes in Sexual Functioning Questionnaire (CSFQ), which were completed at baseline and at the end of 4 and 8 weeks of treatment. The primary endpoint was the average intra-patient change from baseline to four weeks in the CSFQ subscales between the two arms. A total of 64 patients per group were needed to provide 80% power to detect a difference of 8 units between the treatment means. Two-sided alternative hypothesis testing and a 5% Type I error rate were used. Results: One hundred fifty women were enrolled onto this study. Complete data were available for 132 women. For those on active testosterone cream, serum bioavailable testosterone levels increased significantly over placebo, with a mean change from baseline of 12 and 10 ng/dl for the first and second period, respectively (p<.0001). The average intra-patient change from baseline to week 4 in libido was 5.5 on testosterone and 4.4 on placebo (p=0.58). No carryover effect was detected. The difference in average intra-patient changes from baseline for the entire crossover design between the two arms was only 1.1 points (95% confidence interval of -1.2 to 3.4, p=0.35). Conclusion: Testosterone is not a panacea for libido troubles in women with a history of cancer. Further studies are needed to determine whether there is a role for transdermal testosterone in this population.

No significant financial relationships to disclose.

Initial results of a phase II study of biweekly pemetrexed and gemcitabine in patients with advanced NSCLC

7128

Background: Pemetrexed (P), a multi-targeted antifolate, is synergisitic with gemcitabine (G) in preclinical models. A phase I study examining a biweekly schedule established a recommended phase 2 dose of G 1500 mg/m2 followed by P 500mg/m2. Methods: Patients with Stage IIIB (with pleural effusion) or IV NSCLC, ECOG PS of 0 or 1, no prior systemic chemotherapy, immunotherapy, or biological therapy were enrolled. G was infused over 30 minutes, followed immediately by P given intravenously over 10 minutes once on day 1 every 14 days. Cycles were repeated until 12 treatments or progressive disease. All patients received folic acid, vitamin B12 and steroid prophylaxis. Results: Data on 53 patients (29 male, 24 female) are currently available. Median age: 64 (range: 35, 80), ECOG performance status 0:1 = 38%:60%, Stage IIIB:IV = 19%:81%. Three hundred twelve cycles of treatment were administered with 14 dose reductions (26.4%); median number of doses was 5 for both G and P, and median dose intensity was 98.05% for both G and P. Response data included 1 complete response (1.9%), 14 partial responses (26.4%), 24 stable diseases (45.3%), and 10 progressive diseases (18.9%), with a response rate of 28.3% (95% CI: 16.8–42.3%). Patient-based Grade 3/4 hematologic events included febrile neutropenia (9.4%), neutropenia (28.3%), and thrombocytopenia (1.9%). Grade 3/4 non-hematologic events included fatigue (22.6%), dyspnea (7.5%), dehydration (7.5%), diarrhea (5.7%), constipation (3.8%), and pneumonia (1.9%). Preliminary median survival was 7.8 months (95% CI: 6.0–10.8) with 43.4% patients censored and median TTPD was 4.6 months (95% CI: 2.8–6.1). Conclusion: Biweekly G and P appear to be well tolerated in advanced NSCLC. A clinical benefit rate (ORR + SD) of 73.6% indicates activity in patients with advanced NSCLC. The dose intensity for biweekly G and P is higher than a previously reported 6-cycle, 21-day regimen with median dose intensity of 83.2% for P and 82.2% for G (West, et al. Proc ASCO 2005; 7117).

[Table: see text]

Heating and humidifying of carbon dioxide during pneumoperitoneum is not indicated

BACKGROUND

Carbon dioxide (CO2) pneumoperitoneum usually is created by a compressed gas source. This exposes the patient to cool dry gas delivered at room temperature (21 degrees C) with 0% relative humidity. Various delivery methods are available for humidifying and heating CO2 gas. This study was designed to determine the effects of heating and humidifying gas for the intraabdominal environment.

METHODS

For this study, 44 patients undergoing laparoscopic Roux-en-Y gastric bypass were randomly assigned to one of four arms in a prospective, randomized, single-blinded fashion: raw CO2 (group 1), heated CO2 (group 2), humidified CO2 (group 3), and heated and humidified CO2 (group 4). A commercially available CO2 heater-humidifier was used. Core temperatures, intraabdominal humidity, perioperative data, and postoperative outcomes were monitored. Peritoneal biopsies were taken in each group at the beginning and end of the case. Biopsies were subjected staining protocols designed to identify structural damage and macrophage activity. Postoperative narcotic use, pain scale scores, recovery room time, and length of hospital stay were recorded. One-way analysis of variance (ANOVA) and the nonparametric Kruskal-Wallis test were used to compare the groups.

RESULTS

Demographics, volume of CO2 used, intraabdominal humidity, bladder temperatures, lens fogging, and operative times were not significantly different between the groups. Core temperatures were stable, and intraabdominal humidity measurements approached 100% for all the patients over the entire procedure. Total narcotic dosage and pain scale scores were not statistically different. Recovery room times and length of hospital stay were similar in all the groups. Only one biopsy in the heated-humidified group showed an increase in macrophage activity.

CONCLUSIONS

The intraabdominal environment in terms of temperature and humidity was similar in all the groups. There was no significant difference in the intraoperative body temperatures or the postoperative variable measured. No histologic changes were identified. Heating or humidifying of CO2 is not justified for patients undergoing laparoscopic bariatric surgery.

High-energy transurethral microwave thermotherapy: symptomatic vs urodynamic success

OBJECTIVE

To evaluate the subjective and objective treatment results of high-energy transurethral microwave thermotherapy (TUMT) for symptomatic benign prostatic hyperplasia (BPH), and investigate the possible variables for predicting symptomatic and/or urodynamic success.

PATIENTS AND METHODS

Between October 1998 and October 2000, 40 men with BPH underwent high-energy TUMT using the Targis device (Urologix, Inc., Minneapolis, MN, USA). Evaluation after treatment included a clinical determination of the symptom score, a urodynamic assessment by peak flow rate and pressure-flow, magnetic resonance imaging (MRI), transrectal ultrasonography and endoscopy. The objective and subjective success was correlated with several variables before, during and after treatment.

RESULTS

All patients completed at least 1 year of follow-up after TUMT as monotherapy. The symptom score improved from a median (range) of 20.5 (11-28) initially to 9 (0-28) (P < 0.001). Twenty-two patients (55%) had a marked and 11 (28%) a moderate response, giving an overall subjective success rate of 83%. Similarly, there was a significant improvement in peak flow rate, from 9.2 (4.4-13.4) to 15 (3.3-22.9) mL/s (P < 0.001). Twenty-one patients (53%) had a maximum flow rate of > 15 mL/s while in eight (20%) it was 10-15 mL/s. Only 20 patients changed from unobstructed on the pressure-flow nomogram, i.e. an overall objective success rate of 50%. Gadolinium-enhanced T1-weighted MRI 1 week after treatment showed a median (range) perfusion defect of 20.7 (5.5-76.6)% of the total gland volume. Despite this persisting in all patients, a well-defined cavity was apparent in only in seven (18%) at the final evaluation. Cystoscopy 1 month after therapy showed evidence of necrotic tissue occupying the prostatic fossa in all patients. Younger patients were more likely to be urodynamically successful, and a higher grade of obstruction predicted symptomatic success.

CONCLUSION

High-energy TUMT can induce considerable necrosis of the prostate, as shown by MRI and cystoscopy. Although there was an adequate improvement in most patients' symptoms, there was a successful urodynamic change to unobstructed in only half the patients. Younger patients and those with a higher grade of obstruction were more likely to have urodynamic and symptomatic success, respectively.

Allograft rejection predicts the occurrence of late-onset cytomegalovirus (CMV) disease among CMV-mismatched solid organ transplant patients receiving prophylaxis with oral ganciclovir

The natural history of cytomegalovirus (CMV) disease associated with solid organ transplantation has been modified as a result of the widespread use of antiviral prophylaxis. Anecdotal reports have indicated a reduction of CMV disease at the expense of its later occurrence after completion of ganciclovir prophylaxis. The present study investigated the occurrence of CMV disease and its risk factors among 37 liver and kidney transplant recipients with CMV D+/R- status who received oral ganciclovir during the first 100 days posttransplantation. CMV disease occurred in 9 patients (24.3%) at a median of 144 days posttransplantation (range, 95-190 days). Allograft rejection was found to be strongly associated with the occurrence of late-onset CMV disease (risk ratio, 6.6; 95% confidence interval, 1.4-32.1; P=.02). Thus, CMV D+/R- solid organ transplant recipients receiving 3 months of oral ganciclovir who develop allograft rejection during the period of antiviral prophylaxis may benefit from extended and/or enhanced antiviral prophylaxis to prevent late-onset CMV disease.

Minimally invasive therapies for benign prostatic hyperplasia

Currently, 3 categories of treatment are available for men with benign prostatic hyperplasia (BPH): (1) medicine, such as alpha-blockers and finasteride; (2) minimally invasive treatment, such as transurethral microwave thermotherapy and interstitial ablation using either radiofrequency or laser; and (3) surgical therapy. The 1990s have seen an explosion of transurethral technology to treat symptoms caused by bladder outlet obstruction secondary to BPH. Unlike surgical debulking procedures, the minimally invasive therapies attempt to treat patients without general or regional anesthesia, and even ambulatory procedures are performed in the office. Because of the demographics of patients with BPH, it is hoped that these minimally invasive options will relieve symptoms without any surgical complications and the side effects and compliance issues associated with medical therapy. It is important that urologists have a clear understanding of the clinical usefulness of these devices, so that the overall role of such treatment may be determined by science rather than marketing. Clinically, the degree of symptom score, peak flow, and quality-of-life improvement seen with all the minimally invasive techniques are similar. The techniques may differ in their ability to reach the maximum number of responders and achieve an acceptable duration of response, and the need for analgesia/sedation associated with each technique. This study will define the minimally invasive therapies and present the differences in catheter design and technique. The pathologic basis for these therapeutic options and the advantages and disadvantages of each will be discussed. Urologists must decide which therapy can be used in their office practice. The maximum numbers of responders and enhanced durability of the treatment can be achieved based on realistic expectations, proper selection of patients, and complete information on the potential of these devices.

Impaired mucosal immunity in L-selectin-deficient mice orally immunized with a Salmonella vaccine vector

Lymphocyte trafficking in the gastrointestinal tract is primarily mediated by interactions with the mucosal addressin cell adhesion molecule 1 and its lymphocyte ligand, alpha(4)beta(7), and partly by L-selectin (L-Sel) interactions with peripheral node addressin coexpressed on some mucosal addressin cell adhesion molecule 1. We inquired whether intestinal responses in mice lacking L-Sel would be enhanced. L-Sel-deficient (L-Sel(-/-)) mice were orally immunized with either Salmonella vaccine vector or Salmonella vector-expressing colonization factor Ag I (CFA/I) from enterotoxigenic Escherichia coli. In L-Sel(-/-) mice, mucosal IgA anti-CFA/I fimbrial responses were greatly reduced, and systemic IgG2a anti-CFA/I fimbrial responses were 26-fold greater compared with C57BL/6 (L-Sel(+/+)) mice. L-Sel(-/-) Peyer's patch (PP) CD4(+) Th cells revealed IFN-gamma-dominated responses and an unprecedented absence of IL-4, whereas the expected mixed Th cell phenotype developed in L-Sel(+/+) mice. PP CD4(+) Th cell anti-Salmonella responses were nearly nonexistent in L-Sel(-/-) mice immunized with either Salmonella vaccine. Splenic CD4(+) Th cell anti-Salmonella responses were reduced but did show cytokine production in Ag restimulation assays. Increased colonization of PP and spleen was noted only with the Salmonella vector in L-Sel(-/-) mice, resulting in increased splenomegaly, suggesting that the Salmonella-CFA/I vaccine was not as infectious or that the presence of the fimbriae improved clearance, possibly because of reduced neutrophil recruitment. However, sufficient anti-Salmonella immunity was induced, because Salmonella vector-immunized L-Sel(-/-) mice showed complete protection against wild-type Salmonella challenge, unlike L-Sel(+/+) mice. This evidence shows that L-Sel is important for development of mucosal immunity, and absence of L-Sel is protective against salmonellosis.

N-terminal fatty-acylation of sonic hedgehog enhances the induction of rodent ventral forebrain neurons

The adult basal ganglia arise from the medial and lateral ganglionic eminences, morphologically distinct structures found in the embryonic telencephalon. We have previously shown that temporal changes in sonic hedgehog (Shh) responsiveness determine the sequential induction of embryonic neurons that populate the medial and lateral ganglionic eminences. In this report, we show that Shh-mediated differentiation of neurons that populate the lateral ganglionic eminence express different combinations of the homeobox-containing transcription factors Dlx, Mash1 and Islet 1/2. Furthermore, we show that N-terminal fatty-acylation of Shh significantly enhances its ability to induce the differentiation of rat E11 telencephalic neurons expressing Dlx, Islet 1/2 or Mash1. Recent evidence indicates that in utero injection of the E9.5 mouse forebrain with retroviruses encoding wild-type Shh induces the ectopic expression of Dlx2 and severe deformities in the brain. In this report, we show that Shh containing a mutation at the site of acylation prevents either of these phenotypes. These results suggest that N-terminal fatty-acylation of Shh may play an important role in Shh-dependent signaling during rodent ventral forebrain formation.

Sampling artifacts from the use of denuder tubes with glycerol based coatings in the measurement of atmospheric particulate matter

Chemical speciation studies use sampling configurations that often require the deployment of denuder tubes of various types to measure certain species or control particulate sampling artifacts. Concurrent sets of measurements on Teflon membrane and quartz filters in specific sampling configurations were used to evaluate the potential influence of denuder tubes with glycerol-based coatings on particulate mass and carbon measurements on downstream filters. Positive biases were observed in the measurement of gravimetric mass and carbon on Teflon and quartz filters, respectively, downstream of sodium carbonate/ glycerol and citric acid/glycerol coated denuder tubes relative to those without upstream denuder tubes. The magnitude of the bias is dependent on the level of ambient particulate loading.

Functional analysis and treatment of inappropriate verbal behavior

The present study examined the possible function of inappropriate verbal behavior of an adult man who had been diagnosed with both mental retardation and psychosis. Results of a functional analysis indicated that inappropriate verbal utterances were maintained by attention. An intervention consisting of the differential reinforcement of appropriate verbal behavior effectively reduced the inappropriate behavior.

Estimating the benefits of solitary pancreas transplantation in nonuremic patients with type 1 diabetes mellitus: a theoretical analysis

BACKGROUND

The goal of early pancreas transplantation in type 1 diabetes mellitus is to achieve euglycemia and thereby prevent the renal, retinal, and vascular complications of this disease. The purpose of this analysis was to examine the conditions and assumptions that would make early solitary pancreas a viable therapeutic option.

METHODS

A Markov model was constructed to compare outcomes for patients with type 1 diabetes mellitus and early overt nephropathy assigned to either standard insulin therapy or solitary pancreas transplantation. Probabilities for development of end stage renal disease (ESRD), blindness, mortality, and direct health care costs were taken from the literature. Utility scores for the relevant health states were determined by the standard gamble method on 16 type 1 diabetic patients suitable for pancreas transplantation.

RESULTS

Assuming a baseline graft life expectancy for the pancreas of 10 years, early pancreas transplantation could provide 0.42 more life years and 2.2 more quality adjusted life years (discounted at 3%) to patients above standard insulin therapy. The model was sensitive to estimates of pancreas graft life expectancy (<8 years being inadequate to extend patient life), timing of pancreas transplantation with respect to rate of progression to ESRD, and drug nephrotoxicity rates. The incremental costs (charges) for early pancreas transplantation over standard therapy were estimated to be modestly high (about $56,600/quality adjusted life year for the baseline case). Pancreas transplant costs were also a very sensitive parameter in the cost utility analysis.

CONCLUSIONS

The success of early solitary pancreas transplantation may well be at the stage to consider a trial in selected type 1 diabetic patients at risk for renal and retinal disease.

Cell-kill modeling of microwave thermotherapy for treatment of benign prostatic hyperplasia

PURPOSE

We investigated whether cell-kill modelling could be used as a mean for predicting the outcome of microwave thermotherapy for benign prostate hyperplasia (BPH).

METHODS

The two models--Henriques' damage integral and Jung's compartment model--were implemented in a computer program. Real treatment data for 22 patients with BPH who were in chronic retention were used as input, including measured intraprostatic temperatures and microwave power. To test if modelling gives results that are consistent with actual observations, comparison with transrectal ultrasound (TRUS) measurements of the prostate volume before and after treatment was made. The sensitivity of the computer model for variations in the heat cytotoxicity and the temperature probe location in the adenoma was also tested.

RESULTS

The average TRUS volume reduction 3 months after treatment was 26 cc, whereas the corresponding cell kill calculation was 27 cc. The computer model appears to be rather insensitive to minor uncertainties in heat sensitivity and location of the intraprostatic reference temperature sensors.

CONCLUSION

Cell-kill modelling appears to give results that are consistent with actual observations. The coagulated tissue volume is calculated in real time during the treatment, thereby providing an immediate prediction of the treatment outcome. By using cell-kill modelling, the endpoint of a treatment can be set individually; e.g., when a certain volume reduction has been achieved.

Use of permanent interstitial temperature self-regulating rods for ablation of prostate cancer

BACKGROUND AND PURPOSE

We have examined a new technique for the thermal treatment of prostate cancer involving the percutaneous placement of small magnetic alloy rods into the gland in a procedure analogous to the placement of permanent brachytherapy seeds. When the patient and the implanted rods are placed in an extracorporeal alternating magnetic field, the rods heat and can produce tissue necrosis. The rods are temperature self-regulating and produce temperatures no higher than their preprogrammed regulation value. The rods are biocompatable permanent implants, comprised of cobalt and palladium.

MATERIALS AND METHODS

We examined rods that heat to 55 degrees, 60 degrees, and 70 degrees C. Patients are treated for 1-hour sessions and easily have multiple sessions.

RESULTS

Isolated rods produced little or asymmetrical necrosis. However, arrays of 70 degrees C rods placed within 1 cm of each other caused consistent necrosis between the rods. The temperature at the edge of the array dropped off quickly, and therefore, the rods can be placed within 2 mm of the capsule even posteriorly near the rectum.

CONCLUSIONS

Arrays of high-temperature rods can be employed for tissue ablation, while lower-temperature arrays could be used to produce hyperthermia in order to achieve synergism with adjuvant radiation therapy. The technique is applicable in an outpatient setting.

Asthma aggravation, combustion, and stagnant air

BACKGROUND

The relationship between current concentrations of ambient air pollution and adverse health effects is controversial. We report a meteorological index of air stagnation that is associated with daily visits to the emergency department for asthma in two urban areas.

METHODS

Data on daily values of a stagnation persistence index and visits to the emergency department for asthma were collected for approximately two years in Spokane, Washington, USA and for 15 months in Seattle, Washington, USA. The stagnation persistence index represents the number of hours during the 24 hour day when surface wind speeds are less than the annual hourly median value, an index readily available for most urban areas. Associations between the daily stagnation persistence index and daily emergency department visits for asthma were tested using a generalised additive Poisson regression model. A factor analysis of particulate matter (PM(2.5)) composition was performed to identify the pollutants associated with increased asthma visits.

RESULTS

The relative rate of the association between a visit to the emergency department for asthma and the stagnation persistence index was 1. 12 (95% CI 1.05 to 1.19) in Spokane and 1.21 (95% CI 1.09 to 1.35) in Seattle for an increase of 11 and 10 hours, respectively, of low wind speed in a given day. The stagnation persistence index was only correlated with one set of factor loadings; that cluster included the stagnation persistence index, carbon monoxide, and organic/elemental carbon.

CONCLUSION

Increased air stagnation was shown to be a surrogate for accumulation of the products of incomplete combustion, including carbon monoxide and fine particulate levels of organic and elemental carbon, and was more strongly associated with asthma aggravation than any one of the measured pollutants.

Analysis of capsid formation of human polyomavirus JC (Tokyo-1 strain) by a eukaryotic expression system: splicing of late RNAs, translation and nuclear transport of major capsid protein VP1, and capsid assembly

Human polyomavirus JC (JCV) can encode the three capsid proteins VP1, VP2, and VP3, downstream of the agnoprotein in the late region. JCV virions are identified in the nucleus of infected cells. In this study, we have elucidated unique features of JCV capsid formation by using a eukaryotic expression system. Structures of JCV polycistronic late RNAs (M1 to M4 and possibly M5 and M6) generated by alternative splicing were determined. VP1 would be synthesized from M2 RNA, and VP2 and VP3 would be synthesized from M1 RNA. The presence of the open reading frame of the agnoprotein or the leader sequence (nucleotides 275 to 409) can decrease the expression level of VP1. VP1 was efficiently transported to the nucleus in the presence of VP2 and VP3 but distributed both in the cytoplasm and in the nucleus in their absence. Mutation analysis indicated that inefficiency in nuclear transport of VP1 is due to the unique structure in the N-terminal sequence, KRKGERK. Within the nucleus, VP1 was localized discretely and identified as speckles in the presence of VP2 and VP3 but distributed diffusely in their absence. These results suggest that VP1 was efficiently transported to the nucleus and localized in the discrete subnuclear regions, possibly with VP2 and VP3. By electron microscopy, recombinant virus particles were identified in the nucleus, and their intranuclear distribution was consistent with distribution of speckles. This system provides a useful model with which to understand JCV capsid formation and the structures and functions of the JCV capsid proteins.

Spatial and temporal measurements of NO2 in an urban area using continuous mobile monitoring and passive samplers

This paper describes the use of a continuous mobile monitor and passive samplers to estimate the spatial distribution of NO2 in an urban area for the purpose of siting a continuous monitor to measure population exposure. Monitoring sites were sites selected based on the State and Local Air Monitoring Stations (SLAMS) and National Air Monitoring Station (NAMS) siting criteria required by the U.S. Environmental Protection Agency (U.S. EPA). SLAMS monitoring objectives define scales in which the NO2 concentration and land use are homogeneous. The SLAMS scales relevant to NO2 monitoring for NAMS NO2 monitoring sites are neighborhood (0.5 to 4 km), and urban (several to 50 km). SLAMS siting objectives also define four categories of sites: highest concentration, representative concentration, impacts of major sources, and background sites. Mobile monitoring with a Scintrex LMA-3 luminal monitor was used on a neighborhood scale to measure the NO2 concentration at sites that covered a large geographical area. Passive samplers were then located at candidate mobile monitoring locations for long-term sampling which covered the neighborhood to the urban scale. These two methods complement each other by combining short-term continuous measurements and integrated long-term measurements which reflect the National Ambient Air Quality Standard for NO2 which is based on an annual average. The neighborhood site with the highest concentration was not only in the area of highest population density, but was also representative of the larger urban scale. The magnitude of this urban scale is approximately 20 km.

Episodes of high coarse particle concentrations are not associated with increased mortality

Fine particle concentration (i.e., particles <2.5 microm in aerodynamic diameter; PM2.5), but not coarse particle concentration, was associated with increased mortality in six U.S. cities. Others criticized this result, arguing that it could result from differences in measurement error between the two size ranges. Fine particles are primarily from combustion of fossil fuel, whereras coarse particles (i.e., particles between 2.5 and 10 microm in aerodynamic diameter) are all crustal material, i.e., dust. One way to determine if coarse particles are a risk for mortality is to identify episodes of high concentrations of coarse, but not fine, particles. Spokane, Washington, is located in an arid area and is subject to occasional dust storms after crops have been harvested. Between 1989 and 1995, we identified 17 dust storms in Spokane. The 24-hr mean PM10 concentration during those storms was 263 microg/m3. Using control dates that were the same day of the year in other years (but with no dust storm on that day) and that had a mean PM10 concentration of 42 microg/m3, we compared the rate of nonaccidental deaths on the episode versus nonepisode days. There was little evidence of any risk [relative risk (RR) = 1.00; 95% confidence interval (CI), 0.81-1.22] on the episode days. Defining episode deaths as those occurring on the same or following day as the dust storm produced similar results (RR = 1.01; CI, 0.87-1.17). Sensitivity analyses, which tested more extensive seasonal control, produced smaller estimates. We conclude that coarse particles from windblown dust are not associated with mortality risk.

Airborne Particulate Matter Size Distributions in an Arid Urban Area

While there is a growing body of data on the health effects of particulate matter, there is little information available from areas that experience frequent dust storms, such as Spokane, WA. As part of a three-year study to investigate the health effects associated with exposure to atmospheric aerosols, ambient particulate matter in Spokane is being characterized according to particle size and chemical composition. In this report, particulate matter concentrations measured using continuous tapered-element oscillating microbalances for three size ranges are discussed. Particles with aerodynamic diameters less than 10 micrometers (PM₁₀), less than 2.5 micrometers (PM₂₅), and less than 1.0 micrometer (PM_1.0) were measured at a residential site; PM₁₀ and PM_2.5 were measured at an industrial site. Based upon 1.5 years of data, PM₁₀ was found, on average, to consist of approximately 40% PM_2.5 at the industrial site and approximately 50% at the residential site, with higher fractions (up to 50% at the industrial site and up to 80% at the residential site) observed in the late fall or early winter (October-November). At the residential site, PM₂₅ was comprised of approximately 80% particles 1.0 micrometer and smaller. Only one windblown dust storm occurred during the sampling period, on July 24, 1994, during which both PM₁₀ and PM_2.5 concentrations were enhanced.

The oncogenic T cell LIM-protein Lmo2 forms part of a DNA-binding complex specifically in immature T cells

The LIM-only protein LMO2 is expressed aberrantly in acute T-cell leukaemias as a result of the chromosomal translocations t(11;14) (p13;q11) or t(7;11) (q35;p13). In a transgenic model of tumorigenesis by Lmo2, T-cell acute leukaemias arise after an asymptomatic phase in which an accumulation of immature CD4(-) CD8(-) double negative thymocytes occurs. Possible molecular mechanisms underlying these effects have been investigated in T cells from Lmo2 transgenic mice. Isolation of DNA-binding sites by CASTing and band shift assays demonstrates the presence of an oligomeric complex involving Lmo2 which can bind to a bipartite DNA motif comprising two E-box sequences approximately 10 bp apart, which is distinct from that found in erythroid cells. This complex occurs in T-cell tumours and it is restricted to the immature CD4(- )CD8(-) thymocyte subset in asymptomatic transgenic mice. Thus, ectopic expression of Lmo2 by transgenesis, or by chromosomal translocations in humans, may result in the aberrant protein interactions causing abnormal regulation of gene expression, resulting in a blockage of T-cell differentiation and providing precursor cells for overt tumour formation.

Viability of Escherichia coli O157:H7 in salami following conditioning of batter, fermentation and drying of sticks, and storage of slices

The fate of Escherichia coli O157:H7 was monitored in salami during conditioning of batter, fermentation and drying of sticks, and storage of slices. The raw batter (75% pork: 25% beef, wt/wt, fat content about 20%) was inoculated with a pediococcal starter culture (about 10(8) CFU/g) and a five-strain cocktail of E. coli O157:H7 ( > or = 2 x 10(7) CFU/g) and stuffed into 104-mm diameter fibrous casings. After being refrigerated at 4 degrees C or being tempered at 13 degrees C, frozen at -20 degrees C, and thawed at 4 degrees C, or being frozen at -20 degrees C, and thawed at 4 degrees C, the inoculated batter was fermented at 24 degrees C and 90% relative humidity (RH) to pH < or = 4.8, dried at 13 degrees C and 65% RH to a moisture/protein ratio of < or = 1.9:1, and then stored at 4 or 21 degrees C under air or vacuum. For salami sticks sampled immediately after drying, appreciable differences were evident among the various batter-conditioning treatments; pathogen numbers were reduced from original levels by 2.1, 1.6, or 1.1 log10 units when batter was tempered, frozen, and thawed, frozen and thawed, or refrigerated, respectively. Similarly, regardless of storage temperature or atmosphere, within 7 days salami slices cut from sticks prepared from batter that was tempered, frozen, and thawed (2.7- to 4.9-log10-unit reduction) or frozen and thawed (2.3- to 4.8-log10-unit reduction) displayed a greater impact on pathogen numbers than slices cut from sticks prepared from batter that was refrigerated (1.6- to 3.1-log10-unit reduction). The effects of batter conditioning notwithstanding, a greater reduction in levels of E. coli O157:H7 was observed when slices were stored at 21 degrees C compared to otherwise similar slices stored at 4 degrees C. After storage for 60 days the pathogen was only detected by enrichment in slices stored at 21 degrees C, whereas pathogen levels ranged from 1.4 to 4.5 log10 CFU/g in slices stored at 4 degrees C. Differences related to storage atmosphere were first observed after slices were stored for 21 days. Such differences were more readily demonstrable after 60 and 90 days, with pathogen numbers for treatments that were statistically different ranging from 0.6- to 1.5-log10 units higher on slices stored under vacuum than in air. These data emphasize the need to implement multiple barriers to appreciably reduce numbers of E. coli O157:H7 in salami.

Viability of Escherichia coli O157:H7 in pepperoni during the manufacture of sticks and the subsequent storage of slices at 21, 4 and -20 degrees C under air, vacuum and CO2

A raw, pepperoni batter (75% pork:25% beef with a fat content of about 32%) was inoculated with a pediococcal starter culture (about 10(8) cfu/g) and a five-strain cocktail of Escherichia coli O157:H7 (> or = 2 x 10(7) cfu/g), mixed with non-meat ingredients, and then hand-stuffed into 55 mm fibrous casings to form sticks. The numbers of the pathogen were determined before stuffing, after fermentation, after drying/slicing, and after periods of storage. For storage, slices were packaged under air, vacuum or CO2 and stored at -20, 4 and 21 degrees C. Sticks were fermented at 36 degrees C and 85% relative humidity (RH) to < or = pH 4.8 and then dried at 13 degrees C and 65% RH to a moisture/protein ratio (M/Pr) of < or = 1.6:1. Fermentation and drying resulted in the numbers of the pathogen decreasing by about 2 log10 units. During storage, the temperature rather than the atmosphere had the greater effect on pathogen numbers. The greatest reductions in numbers were observed during storage at 21 degrees C, when numbers decreased to about 2 and 3.8 log10 cfu/g within 14 days in product stored under air and vacuum, respectively, and a 5 log10 reduction was observed for both atmospheres within 28 days. Regardless of the storage atmosphere, numbers did not decrease below 3.6 or 3.7 log10 cfu/g after 90 days of storage at -20 or 4 degrees C, respectively. These data confirm that fermentation and drying are sufficient to eliminate only about 2 log10 cfu/g of E. coli O157:H7 from fermented sausage, and that additional strategies, such as storage for at least 2 weeks at ambient temperature in air, are required to achieve a 5 to 6 log10 reduction in the numbers of the pathogen in sliced pepperoni.

The Hox11 gene is essential for cell survival during spleen development

The HOX11 homeobox gene was identified via the translocation t(10;14) in T cell leukaemia. To determine the function of this gene in mice, null mutations were made using homologous recombination in ES cells to incorporate lacZ into the hox11 transcription unit. Production of beta-galactosidase from the recombinant hox11 allele in +/− mutants allowed identification of sites of hox11 expression which included the developing spleen. Newborn hox11 −/− mice exhibit asplenia. Spleen formation commences normally at E11.5 in hox11 −/− mutant embryos but the spleen anlage undergoes rapid and complete resorption between E12.5 and E13.5. Dying spleen cells exhibit molecular features of apoptosis, suggesting that programmed cell death is initiated at this stage of organ development in the absence of hox11 protein. Thus hox11 is not required to initiate spleen development but is essential for the survival of splenic precursors during organogenesis. This function for hox11 suggests that enhanced cell survival may result from the t(10;14) which activates HOX11 in T cell leukaemias, further strengthening the association between oncogene-induced cell survival and tumorigenesis.

Managing the child infected with HIV

Care of the HIV-infected/exposed infant and child is both routine and challenging. Routine well child care and immunizations are an important part of maintaining and monitoring health status. Challenges arise in the management of acute illnesses and the numerous crises that are experienced by the family caring for that child. Therapy guidelines now provide a logical way in which to initiate antiretroviral treatment and PCP prophylaxis. In HIV-infected children with early disease, common pathogens initially predominate, and only in advanced immune suppression does care become complicated enough to require expert consultation. With increasing numbers of HIV-infected women, perinatally acquired infections in infants will become more common. Early testing and identification will increasingly be important as a way to impact on the significant morbidity and mortality seen in infants less than 6 months old. A caring, compassionate, and comprehensive approach to the care of HIV-infected infants and children results in increased survival and lengthening of disease-free time. Providing this vitally needed care is both satisfying and stimulating.