Risk of brainstem necrosis in pediatric patients with central nervous system malignancies after pencil beam scanning proton therapy.

Background: Radiation therapy (RT) plays an important role in management of pediatric central nervous system (CNS) malignancies. Centers are increasingly utilizing pencil beam scanning proton therapy (PBS-PT). However, the risk of brainstem necrosis has not yet been reported. In this study, we evaluate the rate of brainstem necrosis in pediatric patients with CNS malignancies treated with PBS-PT.Material and methods: Pediatric patients with non-hematologic CNS malignancies treated with PBS-PT who received dose to the brainstem were included. All procedures were approved by the institutional review board. Brainstem necrosis was defined as symptomatic toxicity. The actuarial rate was analyzed by the Kaplan Meier method.Results: One hundred and sixty-six consecutive patients were reviewed. Median age was 10 years (range 0.5-21 years). Four patients (2.4%) had prior radiation. Median maximum brainstem dose in the treated course was 55.4 Gy[RBE] (range 0.15-61.4 Gy[RBE]). In patients with prior RT, cumulative median maximum brainstem dose was 98.0 Gy [RBE] (range 17.0-111.0 Gy [RBE]). Median follow up was 19.6 months (range, 2.0-63.0). One patient who had previously been treated with twice-daily radiation therapy and intrathecal (IT) methotrexate experienced brainstem necrosis. The actuarial incidence of brainstem necrosis was 0.7% at 24 months (95% CI 0.1-5.1%).Conclusion: The rate of symptomatic brainstem necrosis was extremely low after treatment with PBS-PT in this study. Further work to clarify clinical and dosimetric parameters associated with risk of brainstem necrosis after PBS-PT is needed.

Radical scavenging of poly(methyl methacrylate) bone cement by rifampin and clinically relevant properties of the rifampin-loaded cement.

OBJECTIVES: The objective of this study was to characterize the effect of rifampin incorporation into poly(methyl methacrylate) (PMMA) bone cement. While incompatibilities between the two materials have been previously noted, we sought to identify and quantify the cause of rifampin's effects, including alterations in curing properties, mechanical strength, and residual monomer content. METHODS: Four cement groups were prepared using commercial PMMA bone cement: a control; one with 1 g of rifampin; and one each with equimolar amounts of ascorbic acid or hydroquinone relative to the amount of rifampin added. The handling properties, setting time, exothermic output, and monomer loss were measured throughout curing. The mechanical strength of each group was tested over 14 days. A radical scavenging assay was used to assess the scavenging abilities of rifampin and its individual moieties. RESULTS: Compared with control, the rifampin-incorporated cement had a prolonged setting time and a reduction in exothermic output during polymerization. The rifampin cement showed significantly reduced strength and was below the orthopaedic weight-bearing threshold of 70 MPa. Based on the radical scavenging assay and strength tests, the hydroquinone structure within rifampin was identified as the polymerization inhibitor. CONCLUSION: The incorporation of rifampin into PMMA bone cement interferes with the cement's radical polymerization. This interference is due to the hydroquinone moiety within rifampin. This combination alters the cement's handling and curing properties, and lowers the strength below the threshold for weight-bearing applications. Additionally, the incomplete polymerization leads to increased toxic monomer output, which discourages its use even in non-weight-bearing applications.Cite this article: G. A. Funk, E. M. Menuey, K. A. Cole, T. P. Schuman, K. V. Kilway, T. E. McIff. Radical scavenging of poly(methyl methacrylate) bone cement by rifampin and clinically relevant properties of the rifampin-loaded cement. Bone Joint Res 2019;8:81-89. DOI: 10.1302/2046-3758.82.BJR-2018-0170.R2.

A comparison of screening methods in two early phase oral leukoplakia clinical trials.

OBJECTIVES/INTRODUCTION: Clinical trial accrual for oral dysplasia is difficult in the United States and elsewhere. Patients with dysplastic oral leukoplakia progress to frank invasive carcinoma at a rate of 5-37% over 5 years. We compared two clinical trial screening efforts to hopefully devise better accrual strategies to these types of clinical trials. METHODS: For the first trial, we identified 244 patients with dysplastic oral leukoplakia in our university database and a media campaign. Patients were notified and screened by examination and biopsy. For the second clinical trial, we established a preneoplastic lesions clinic and teaching and communications network with regional oral healthcare professionals. RESULTS: Only one of 244 patients accrued to the first clinical trial through an organized screening effort based on database/medical records review. The second clinical trial accrued 16/30 screened patients through redirected efforts in teaching, communications, and a preneoplastic lesions clinic. CONCLUSION: We conclude that significant difficulties resulted from medical record/database review of leukoplakia patients as a screening method for leukoplakia clinical trial entry. We feel that persistent direct contact and education of healthcare professionals who are likely to examine leukoplakia patients improved accrual to the second clinical trial.

Cathinone (Khat) and methcathinone (CAT) in urine specimens: a gas chromatographic-mass spectrometric detection procedure.

A gas chromatographic-mass spectrometric procedure for detection of cathinone (Khat) and methcathinone (CAT) in urine was developed. The compounds were detected as 4-carboethoxyhexafluorobutyryl derivatives. Three ions for the drugs and two ions for the internal standards were monitored. The drugs were identified by comparing retention times and ion ratios with that of reference compounds. The concentrations were measured by using amphetamine-d6 as internal standard for cathinone and methamphetamine-d9 as internal standard for methcathinone, and were linear over the range of 25-5000 ng/mL for cathinone and 12.5-5000 ng/mL for methcathinone. The overall recoveries of cathinone and methcathinone were 86 and 78%, respectively. Intrarun and inter-run variations were < 20%. To verify that the drugs are not metabolites of over-the-counter medications, cathinone and methcathinone were tested in urine specimens collected from individuals who ingested phenylpropanolamine and pseudoephedrine. None of the specimens showed the keto-amines as the metabolic products. When the procedure was applied to test 66 amphetamine-immunoassay-positive specimens containing no amphetamine or methamphetamine, two specimens were found positive for cathinone (118 and 3266 ng/mL) and six specimens were found positive for methcathinone (13-91 ng/mL).

Anaerobic benzene oxidation coupled to nitrate reduction in pure culture by two strains of Dechloromonas.

Benzene contamination is a significant problem. It is used in a wide range of manufacturing processes and is a primary component of petroleum-based fuels. Benzene is a hydrocarbon that is soluble, mobile, toxic and stable, especially in ground and surface waters. It is poorly biodegraded in the absence of oxygen. However, anaerobic benzene biodegradation has been documented under various conditions. Although benzene biomineralization has been demonstrated with nitrate, Fe(III), sulphate or CO2 as alternative electron acceptors, these studies were based on sediments or microbial enrichments. Until now there were no organisms in pure culture that degraded benzene anaerobically. Here we report two Dechloromonas strains, RCB and JJ, that can completely mineralize various mono-aromatic compounds including benzene to CO2 in the absence of O2 with nitrate as the electron acceptor. This is the first example, to our knowledge, of an organism of any type that can oxidize benzene anaerobically, and we demonstrate the potential applicability of these organisms to the treatment of contaminated environments.

Consumption and quantitation of delta9-tetrahydrocannabinol in commercially available hemp seed oil products.

There has been a recent and significant increase in the use and availability of hemp seed oil products. These products are being marketed as a healthy source of essential omega fatty acids when taken orally. Although the health aspects of these oils is open to debate, the probability that oils derived from the hemp seed will contain delta9-tetrahyrdocannabinol (THC) is noteworthy. Recent additions to the literature cite a number of studies illustrating that the ingestion of these products results in urinary levels of the THC metabolite, delta9-tetrahyrdocannabinol carboxylic acid (THCA), well above the administrative cutoff (50 ng/mL) used during random drug screens. Testing performed by our laboratory found that the concentration of THC in hemp oil products has been reduced considerably since the publication of earlier studies. The purpose of this study is to quantitate the THC levels in commercially available hemp oils and to administer those oils tested to THC-free volunteers to determine urine metabolite levels following several 15-g doses. Two extraction protocols were evaluated for removing THC from the oil matrix: a single step liquid-liquid extraction was compared to a two-phase process using both liquid-liquid and solid-phase techniques. Gas chromatography-mass spectrometry was used to determine THC levels in several products: four from Spectrum Essentials (3 bottled oils and 1-g capsules), two from Health from the Sun (1-g capsules and bottled oil) oils, and single samples of both Hempstead and Hempola hemp oils. These hemp oil products contained THC concentrations of 36.0, 36.4, 117.5, 79.5, 48.6, 45.7, 21.0, and 11.5 mg/g, respectively. The Abbott AxSYM FPIA and Roche On-Line KIMS immunoassays were used to screen the urine samples, and GC-MS was used to determine the amount of THC in each oil as well as confirm and quantitate THCA in the urine of study participants immediately before and 6 h after each dose. Peak THCA levels in the participants' urine ranged from 1 to 49 ng/mL. All volunteers were below positive screen and confirmation cutoffs within 48 h after cessation of ingestion.

Metalloporphyrins inhibit beta-hematin (hemozoin) formation.

Metal-substituted protoporphyrin IXs (Cr(III)PPIX (1), Co(III)PPIX (2), Mn(III)PPIX (3), Cu(II)PPIX (4), Mg(II)PPIX (5), Zn(II)PPIX (6), and Sn(IV)PPIX (7)) act as inhibitors to beta-hematin (hemozoin) formation, a critical detoxification biopolymer of malarial parasites. The central metal ion plays a significant role in the efficacy of the metalloprotoporphyrins to inhibit beta-hematin formation. The efficacy of these compounds correlates well with the water exchange rate for the octahedral aqua complexes of the porphyrin's central metal ion. Under these in vitro reaction conditions, metalloporphyrins 5, 6 and 7 are as much as six times more efficacious than the free ligand protoporphyrin IX in preventing beta-hematin formation and four times as efficacious as chloroquine, while metalloporphyrins 3 and 4 are three to four times more effective at preventing beta-hematin formation than the free protoporphyrin IX base. In contrast, the relatively exchange inert metalloporphyrins 1 and 2 are only as efficacious as the free ligand and only two-thirds as effective as chloroquine. Aggregation studies of the heme:MPPIX using UV-Vis and fluorescence spectroscopies are indicative of the formation of pi-pi hetero-metalloporphyrin assemblies. Thus, hemozoin inhibition is likely prevented by the formation of heme:MPPIX complexes through pi-stacking interactions. The ramifications of such hetero-metalloporphyrin assemblies, in the context of the emerging structural picture of hemozoin, are discussed.

The genetics of cancer--a 3D model.

Gene expression microarrays hold great promise for studies of human disease states. There are significant technical issues specific to utilizing clinical tissue samples which have yet to be rigorously addressed and completely overcome. Precise, quantitative measurement of gene expression profiles from specific cell populations is at hand, offering the scientific community the first comprehensive view of the in vivo molecular anatomy of normal cells and their diseased counterparts. Here, we propose a model for integrating-in three dimensions-expression data obtained using the microarray.

Histopathology and molecular biology of ovarian epithelial tumors.

Carcinogenesis in the ovary presents special features related to that organ. First, the preinvasive or even invasive lesions are difficult to detect, which explains why most cases are diagnosed at an advanced stage. Second, the group of tumors of low malignant potential (borderline tumors) are still a controversial category of ovarian lesions. Finally, familial ovarian tumors represent an interesting hereditary model of carcinogenesis at the molecular level. Flow cytometry and immunohistochemistry for proliferative markers or oncogenes provide important prognostic information in patients with ovarian tumors. Molecular data, such as loss of heterozygosity at specific genetic loci, also have been correlated with prognosis. Clonality studies in patients with multiple ovarian/pelvian lesions analyzing chromosome X inactivation patterns and genetic deletions or mutations have contributed to the understanding of the origin of these lesions. New technologies to study gene expression patterns, such as cDNA library construction and DNA microarray technologies, are being applied to study histologic phases of tumor progression, such as normal, preinvasive, and tumor tissues. It is hoped that these studies will contribute important information not only for a better understanding of the process of carcinogenesis, but also for assessing the biology and behavior of individual tumors, determining patient prognosis, and eventually influencing therapy.

cDNA sequencing and analysis of POV1 (PB39): a novel gene up-regulated in prostate cancer.

We recently identified a novel gene (PB39) (HGMW-approved symbol POV1) whose expression is up-regulated in human prostate cancer using tissue microdissection-based differential display analysis. In the present study we report the full-length sequencing of PB39 cDNA, genomic localization of the PB39 gene, and genomic sequence of the mouse homologue. The full-length human cDNA is 2317 nucleotides in length and contains an open reading frame of 559 amino acids which does not show homology with any reported human genes. The N-terminus contains charged amino acids and a helical loop pattern suggestive of an srp leader sequence for a secreted protein. Fluorescence in situ hybridization using PB39 cDNA as probe mapped the gene to chromosome 11p11.1-p11.2. Comparison of PB39 cDNA sequence with murine sequence available in the public database identified a region of previously sequenced mouse genomic DNA showing 67% amino acid sequence homology with human PB39. Based on alignment and comparison to the human cDNA the mouse genomic sequence suggests there are at least 14 exons in the mouse gene spread over approximately 100 kb of genomic sequence. Further analysis of PB39 expression in human tissues shows the presence of a unique splice variant mRNA that appears to be primarily associated with fetal tissues and tumors. Interestingly, the unique splice variant appears in prostatic intraepithelial neoplasia, a microscopic precursor lesion of prostate cancer. The current data support the hypothesis that PB39 plays a role in the development of human prostate cancer and will be useful in the analysis of the gene product in further human and murine studies.

Capillary electrophoretic determination of carboxyhemoglobin concentrations in postmortem blood samples.

The use of capillary electrophoresis (CE) as an alternative to existing methods of quantitation of carbon monoxide (CO) in hemoglobin from postmortem blood samples is presented. The isolation of heme (the portion of the hemoglobin molecule in which CO binding takes place) from hemoglobin is described. Reduced (containing no gas molecules) heme and CO-heme isolated from hemoglobin standards were successfully separated using CE. Heme and CO-heme were also isolated from blood samples of accident victims and analyzed using CE. A quantifiable difference in the CO-heme signals from blood samples containing fatal and nonfatal levels of CO was observed.

Identification and characterization of human metabolites of CAI [5-amino-1-1(4'-chlorobenzoyl-3,5-dichlorobenzyl)-1,2,3-triazole- 4-carboxamide).

The calcium influx inhibitor and cytostatic agent, 5-amino-1-1(4'-chlorobenzoyl-3,5-dichlorobenzyl)-1,2,3-triazole-4-carboxamide (CAI), is in phase I clinical trial for patients with refractory cancer. Additional chromatography peaks were observed during HPLC analysis of patient samples. Identification and characterization of physiological metabolites were undertaken using HPLC techniques developed for their purification from blood, pleural fluid, and urine samples. A hydrophobic metabolite, M1, was purified and functionally characterized. Structural analysis of the purified compound indicated that it is a 3,5-dichloro-4(p-chlorobenzoyl)-benzoic acid. Quantitative analysis of M1 concentration during CAI administration indicated that the rise in M1 concentration lagged behind that of CAI and persisted after CAI was no longer detectable. No clear relationship between CAI or M1 and either toxicity or efficacy was observed. Chromatography of patient blood and urine samples under conditions favoring hydrophilic metabolite detection suggested the presence of a glucuronide compound; this was also indicated by sample treatment with beta-glucuronidase. Attempts at purification did not yield a compound stable for structural analysis. The benzophenone metabolite, M1, was nonfunctional in assays of calcium influx inhibition or proliferation. No pharmacodynamic associations were observed for these metabolites, nor was there pharmacological activity of the M1 as an individual agent. These data suggest that CAI is processed into triazole and benzophenone moieties by phase I metabolism, and these metabolites or the parent compound may be conjugated for excretion by glucuronidation.

Improving physicians' interviewing skills and reducing patients' emotional distress. A randomized clinical trial.

BACKGROUND: Despite high prevalence, emotional distress among primary care patients often goes unrecognized during routine medical encounters. OBJECTIVE: To explore the effect of communication-skills training on the process and outcome of care associated with patients' emotional distress. METHODS: A randomized, controlled field trial was conducted with 69 primary care physicians and 648 of their patients. Physicians were randomized to a no-training control group or one of two communication-skills training courses designed to help physicians address patients' emotional distress. The two training courses addressed communication through problem-defining skills or emotion-handling skills. All office visits of study physicians were audiotaped until five emotionally distressed and five nondistressed patients were enrolled based on patient response to the General Health Questionnaire. Physicians were also audiotaped interviewing a simulated patient to evaluate clinical proficiency. Telephone monitoring of distressed patients for utilization of medical services and General Health Questionnaire scores was conducted 2 weeks, 3 months, and 6 months after their audiotaped office visits. RESULTS: Audiotape analysis of actual and simulated patients showed that trained physicians used significantly more problem-defining and emotion-handling skills than did untrained physicians, without increasing the length of the visit. Trained physicians also reported more psychosocial problems, engaged in more strategies for managing emotional problems with actual patients, and scored higher in clinical proficiency with simulated patients. Patients of trained physicians reported reduction in emotional distress for as long as 6 months. CONCLUSIONS: Important changes in physicians' communication skills were evident after an 8-hour program. The training improved the process and outcome of care without lengthening the visits.

Pharmacokinetics of orally administered carboxyamido-triazole, an inhibitor of calcium-mediated signal transduction.

Carboxyamido-triazole (CAI), inhibits proliferation, invasion, and metastatic potential of a number of cancer cell lines at concentrations greater than 0.4 microgram/ml. The objective of this study was to characterize the pharmacokinetic profile from the first Phase I clinical trial of CAI for the single test dose and multiple daily dosing schedule. Two different p.o. formulations (liquid and gelcap) of CAI were administered. Thirty-nine patients with cancer were enrolled. The dose escalation schema was 100, 125, and 150 mg/m2/day and 200 and 330 mg/m2 every other day of the liquid formulation, plus 100 and 125 mg/m2/day and 200 mg/m2 every other day of the gelcap. The CAI pharmacokinetics are best described by a two-compartment open linear model. The gelcap was more rapidly absorbed than the liquid [time to maximum plasma concentration (Tmax) = 2.06 +/- 1.02 versus 5.31 +/- 3.59 h, P2 = 0.0012] which resulted in higher peak plasma concentrations. There was no evidence of saturable elimination as the dose was increased. The mean steady-state peak concentration was 5.1 +/- 1.0 microgram/ml for the 150 mg/m2/day multiple daily dosing regimen. The terminal half-life of CAI was relatively prolonged, 111 h, and the total body p.o. clearance was low (1.87 liters/h). The peak concentration for all dose levels explored was greater than the targeted concentration suggested by in vitro data for activity. Thus, these data suggest that an effective cytostatic exposure of CAI may be obtained with daily or every other day dosing without severe toxicity.

An evaluation of residency training in interviewing skills and the psychosocial domain of medical practice.

Competent use of interviewing skills is important for the care of all patients but is especially critical, and frequently deficient, in meeting the needs of patients experiencing emotional distress. This study presents an evaluation of a curriculum in communication and psychosocial skills taught to first-year medical residents. A randomized experimental design compared trained and untrained residents' (n = 48) performances with a simulated patient presenting with atypical chest pain and psychosocial distress. Evaluation was based on analysis of videotapes, simulated patient report of residents' behaviors, and chart notation. Trained compared with untrained residents asked more open-ended questions and fewer leading questions, summarized main points more frequently, did more psychosocial counseling, and were rated as having better communication skills by the simulated patient. The use of more focused and psychosocially directed questions, and fewer leading and grab-bag questions, was associated with more accurate diagnoses and management recorded in the medical chart. However, no significant difference was found in the charting practices of trained versus untrained residents.