Investigation of discordant sibling pairs from hereditary breast cancer families and analysis of a rare PMS1 variant

BACKGROUND

It is likely that additional genes for hereditary breast cancer can be identified using a discordant sib pair design. Using this design we identified individuals harboring a rare PMS1 c.605G>A variant previously predicted to result in loss of function.

OBJECTIVES

A family-based design and predictive algorithms were used to prioritize candidate variants possibly associated with an increased risk of hereditary breast cancer. Functional analyses were performed for one of the candidate variants, PMS1 c.605G>A.

METHODS

1) 14 discordant sister-pairs from hereditary breast cancer families were identified. 2) Whole exome sequencing was performed and candidate risk variants identified. 3) A rare PMS variant was identified in 2 unrelated affected sisters but no unaffected siblings. 4) Functional analysis of this variant was carried out using targeted mRNA sequencing.

RESULTS

Genotype-phenotype correlation did not demonstrate tracking of the variant with cancer in the family. Functional analysis revealed no difference in exon 6 incorporation, which was validated by analyzing PMS1 allele specific expression.

CONCLUSIONS

The PMS1 c.605G>A variant did not segregate with disease, and there was no variant-dependent impact on PMS1 exon 6 splicing, supporting this variant is likely benign. Functional analyses are imperative to understanding the clinical significance of predictive algorithms.

Stereotactic Body Radiotherapy - Current Indications

BACKGROUND

Stereotactic body radiotherapy (SBRT) is used to treat localized tumor lesions and consists of applying high doses of radiation to a small number of fractions using specially equipped linear accelerators, modern immobilization devices, and imaging methods, which are considered special, advanced techniques in modern day radiotherapy. SBRT is a very well tolerated, non-invasive, short-term treatment that does not require hospitalization or any complicated preparation. Compared to standard radiotherapy techniques, SBRT allows, due to its precision, significantly higher doses to be applied to the target with less damage to surrounding healthy tissues. If dose constraints are not exceeded, the risk of damage to tissues and organs around the irradiated volume is reduced to minimum. The principle of SBRT is the application of ablative doses of radiation that cause necrosis of the irradiated tissue.

PURPOSE

The aim of this review is to provide a basic overview of SBRT indications, radiation doses used, and potential side effects. It is not intended to be a detailed description of treatment itself (such as discussion of patient fixation systems, management of respiratory movements, or image guided strategies of treatment). This review also discusses rarer indications for SBRT, such as pancreatic carcinoma or hepatocellular carcinoma.

CONCLUSION

Advances in image navigation, radiation planning, and dose application have enabled successful introduction of SBRT as a treatment regimen for many primary tumors and oligometastatic disease. If surgery is not possible or the patient refuses surgery, it is always reasonable to consider SBRT. SBRT has curative potential for the treatment of primary lung or prostate tumors. High-dose irradiation of oligometastases of various primary tumors can lead to long-term survival without disease symptoms, delay administration of toxic systemic therapies, and improve the quality of life of oncological patients. Key words radiotherapy - stereotactic body radiotherapy - review - ablative radiotherapy - lung cancer - prostate cancer - oligometastatic disease This work was supported in part by the Ministry of Health, Czech Republic - Conceptual Development of Research Organization (MMCI 00209805). The results of this research have been acquired within CEITEC 2020 (LQ1601) project with the financial contribution made by the Minis-try of Education, Youths and Sports of the Czech Republic within special support paid from the National Programme for Sustainability II funds. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 30. 10. 2018 Accepted: 4. 11. 2018.

Prognosis of HPV-Positive and -Negative Oropharyngeal Cancers Depends on the Treatment Modality

BACKGROUND

The association between human papilloma virus (HPV) and oropharyngeal carcinoma is a topical issue due mainly to the rapid increase in incidence over recent years. These tumors are etiopathogenetically, epidemiologically, and clinically different from other carcinomas at this location. They have a better prognosis in that they are more chemo-and radiosensitive. Indeed, this has been shown by many extensive retrospective and prospective studies. HPV status is considered an integral part of a standard histopathological examination and is included as a new biological parameter in TNM classification.

MATERIALS AND METHODS

The results of 77 patients who were treated non-surgically for locally advanced oropharyngeal carcinoma at a single university ear, nose, and throat clinic were analyzed retrospectively.

RESULTS

Overall and specific survival of those with HPV-positive (HPV+) tumors was better that those for HPV negative (HPV-) tumors. With the exception of TNM classification, HPV positivity appeared to be the strongest predictor of local control, and of overall and specific survival, regardless of the type of treatment. However, smoking and p53 positivity were significant negative predictors of overall survival. Patients with HPV-associated tumors had a significantly better prognosis, regardless of treatment type. The difference between treatment modalities was confirmed for the whole group of patients, but not for the HPV+ and HPV-patients specifically, most probably due to the small number of patients enrolled.

CONCLUSION

The results obtained herein may constitute the first step toward the concept of treatment de-escalation in those with HPV-associated oropharyngeal carcinoma; however, this decision can be based only on the results of current extensive randomized trials. Specification of the optimal de-escalation scheme, or the choice of treatment modality, for which the difference in treatment results is most pronounced, has yet to be identified. This work was supported by grants of the Ministry of Health of the Czech Republic IGA NT12483-4/2011 and AZV 15-31627A. he authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 21. 9. 2018 Accepted: 14. 5. 2019.

Effect of Tumor Size and p16 Status on Treatment Outcomes - Achievement of Complete Remission in Prospectively Followed Patients with Oropharyngeal Tumors

BACKGROUND

Oropharyngeal squamous cell tumors associated with human papillomavirus infection (p16 positive tumors) have better prognosis than p16 negative tumors regardless of the more advanced stage of the disease. Tumor volume (GTVt+n) is generally an important factor affecting treatment results of ionizing radiation. The aim of this prospective non-randomized study is to evaluate the effect of tumor volume on the (chemo)radiation treatment results in a group of patients with p16 negative and p16 positive oropharyngeal tumors.

PATIENTS AND METHODS

Patients with confirmed squamous cell tumor of the oropharynx of stages III and IV, according to the 7th version of the TNM (tumor-nodes-metastases) classification, were eligible for this study. The main exclusion criteria were palliative treatment, neoadjuvant chemotherapy or planned concomitant therapy with cetuximab. Patients were treated according to standardized protocols with curative intent. Primary tumor volume (GTVt) and involved nodes volume (GTVn) were obtained from radiotherapy planning system for further statistical analysis. The differences in tumor volumes between the groups according to p16 expression were assessed with subsequent testing of probability to achieve complete remission (CR) of the disease in both groups.

RESULTS

In total, 49 patients - 84% men, median age 60.5 years, 25 (51%) patients p16 positive, 40 (82%) underwent concomitant chemoradiotherapy. Median of GTVt in the whole patients group is 40.2 ccm, GTVn 11.78 ccm and median volume of the whole tumor burden (GTVt+n) 70.21 ccm (range 11.05-249). Median of GTVn was greater in the p16 positive cohort (p = 0.041). In the entire group, the median time to reach CR was 91 days (95% CI 86-107 days) from the end of radiotherapy. In the group of p16 negative patients, 14 achieved CR (61%) out of 23 patients, in p16 positive group 20 (80%) out of 25 patients (p = 0.111). P16 negative patients had a longer time to CR (p = 0.196, HR 1.58, 95% CI 0.79-3.18). None of the independently assessed volumetric parameters of the tumor (GTVt, GTVn, GTVt+n) affected CR in the p16 positive patients group, while there was a significant impact of the whole tumor burden (GTVt+n) in the p16 negative cohort (median 58.1 ccm in CR patients vs. 101.9 ccm, p = 0.018).

CONCLUSION

We have showed less GTVt+n dependence to achieve CR in p16 positive tumors in comparison with p16 negative tumors. Thus, p16 positive oropharyngeal squamous cell cancers should not be withdrawn from the curative treatment intent based on the greater GTVt+n. Key words oropharyngeal neoplasms - p16 status - treatment outcome - tumor burden - complete remission This work was supported by grant of the Ministry of Health of the Czech Republic AZV 15-31627A and by grant of the Ministry of Health of the Czech Republic - Conceptual development of a research organization (MMCI 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 2. 11. 2018 Accepted: 11. 11. 2018.

Ablative dose stereotactic body radiation therapy for oligometastatic disease: a prospective single institution study

Localized, metastasis-directed stereotactic body radiation therapy (SBRT) of oligometastatic disease (OD) is currently rapidly evolving standard of care in many institutions. Further reports of outcomes are required to strengthen the level of evidence in the absence of comparative trials evaluating different practical procedures. The aim of this prospective single institutional study is to analyse, in unselected cohort of patients from real-world clinical practice, the long-term survival, tumor control outcomes and safety of SBRT in OD (radical ablative radiotherapy with biological equivalent dose BED10>100 Gy). In addition to standard toxicity and survival parameters, we report unique outcomes as FFWD - Freedom from widespread dissemination, FFNT - Freedom from the need of subsequent treatment and functional survival with Karnofsky performance status higher than 70%. A total of 110 patients were prospectively evaluated, 60% and 40% were treated for lung and liver oligometastatic disease, respectively. No grade 3 or 4 acute toxicities (CTCAE) were reported. With median follow up of 22.2 months and 2-year overall survival of 88.3%, four patients (6.1%) experienced local progression in the lung SBRT cohort. In the liver SBRT cohort, median follow up was 33 months, 2-year overall survival was 68.5% and 11 patients (25%) experienced local and 36 (81.8%) distal progression. Higher BED10 of 150-170 Gy compared to 100-150 Gy was an independent positive prognostic factor for local progression-free survival for all patients with hazard ratio 0.25. This confirms SBRT ablative radiobiology effects to be independent of OD primary histology and location. The best outcomes in terms of FFNT were observed in the multivariable analysis of patients with 1-2 lung OD compared to both the liver OD cohort and patients with more than 2 lung metastases. Better FFNT in the liver SBRT cohort was observed in patients with 1-2 liver metastases and in patients whose liver OD was irradiated by higher BED10. In conclusion, SBRT is a suitable option for patients who are not surgical candidates; with approximately 30% of patients not requiring subsequent treatment 2 years after SBRT. We believe that this treatment represents a safe and effective option for oligometastatic involvement in patients with various primary tumors.

Patterns of failure after brain metastases radiotherapy: reflections on the importance for treatment and clinical trials reporting

In many ongoing clinical trials, new strategies for radiotherapy of brain metastases are currently being investigated. A post surgical focal cavity stereotactic radiosurgery and the developing role of a hippocampal-sparing whole brain radiotherapy are of the highest importance. The evaluation of spatial patterns of metastases failure after radiotherapy is a powerful tool for assessing the potential benefit of new different radiotherapy approaches, which enables to identify possible directions leading to better radiotherapy techniques and to modify general management for newly diagnosed brain metastases. The purpose of this article is to present a mix between trial data and philosophical point of view for discussion about the importance of systematic evaluation of spatial patterns of failure in all ongoing trials investigating new approaches in local brain metastases treatment.

Toxicity and survival outcomes of adjuvant chemoradiation for gastric and gastroesophageal junction cancer patients treated in period 2006-2009: an institutional experience

Surgical resection is the mainstay of gastric or gastroesophageal junction cancer treatment and has curative potential for patients with early-stage disease. In order to improve the poor survival rates, there are two complementary treatment strategies used at most - perioperative chemotherapy based on UK Magic trial or adjuvant chemoradiation based on INT-0116 trial. Daily treatment decision making should be led also by institutional experiences with toxicity evaluation. We evaluated survival and toxicity outcomes of 47 consecutive patients who underwent adjuvant chemoradiation in our institution in the years 2006-2009. 45Gy in 5 weeks with concurrent two cycles of FUFA Mayo regimen chemotherapy were administrated as part of combined treatment. The acute toxicity was relatively mild (CTCAE scale): grade 2 nausea in 26%, vomiting in 13%, and diarrhoea grade 1 in 15% and general abdominal discomfort in 57% of patients. Grade 3 haematological and infectious complications in 6% and 2% respectively. Late adverse events were as follows: grade 1 esophageal toxicity in 17%, signs of mild chronic esophageal ulceration and esophageal stenosis in 9% of patients (50% of them had tracheoesophageal fistula). The Kaplan- Meier estimate of the median overall survival was 30.5 months with median 25.7 months disease free survival. The overall survival was statistically significantly affected by the amount of removed positive lymph nodes. For the proper evaluation of radiotherapy role in multimodal treatment approach, results of other clinical trials investigating role of concurrent radiotherapy in administration of perioperative chemotherapy will be necessary. Meanwhile, two equally approaches are possible, all having their pros and cons. Institutional toxicity evaluation is recommended in order to provide the best care possible. Keywords: adjuvant chemoradiation, gastric cancer, early toxicity, late toxicity, survival outcomes.

Stereotactic body radiation therapy for colorectal cancer liver metastases; early results

BACKGROUND

Stereotactic body radiation therapy (SBRT) is well feasible and effective method for treatment of colorectal cancer liver metastases.

MATERIALS AND METHODS

From September 2009 to December 2011, 11 patients with 15 inoperable liver metastases of colorectal cancer were treated by SBRT using Varian Clinac iX linear accelerator. We treated 6 men and 5 women of age from 51 to 81 years (median 68). SBRT doses ranged from 40 to 56 Gy (median 54 Gy) and were administered in 3 to 8 fractions.

RESULTS

Local control rates at 2, 4, 6, 9 and 12 months after completion of SBRT were 100%, 91%, 91%, 67% and 50%, respectively. Disease progression-free survival rates at 2, 4, 6, 9 and 12 months were 82%, 82%, 64%, 50% and 50%, respectively. Median follow-up was 15 months. No severe side effects were attributed to the therapy.

CONCLUSION

Our study assessed the feasibility of SBRT in selected group of patients with 1 to 3 colorectal cancer liver metastases with no other treatment option. We achieved excellent local control and very moderate acute and late side effects. Distant metastases were the most common recurrence form after SBRT. SBRT demonstrated excellent local control and resulted in occasional long-term survivors without any serious side effects of therapy.

Campylobacter biofilm phenotype exhibits reduced colonization potential in young chickens and altered in vitro virulence

In this study, we evaluated the ability of different Campylobacter phenotypes (biofilm versus planktonic) to colonize young poultry. It has been suggested that a persistent Campylobacter biofilm reservoir may be involved in the initial contamination of poultry flocks. Campylobacter jejuni cultured adherent to agar was utilized as the biofilm model and C. jejuni cultured in broth was evaluated as the planktonic model. In 2 independent trials, 1-d-old broiler chicks were given 1 of 3 treatments: 1) 10(5) cfu.mL(-1) of C. jejuni cultured in broth, 2) 10(5) cfu.mL(-1) of C. jejuni cultured adherent to agar, or 3) no C. jejuni (negative control). Cecal contents of all birds were evaluated by culturing 12 d after the initial challenge with C. jejuni. In both trials, birds challenged with C. jejuni cultured in broth had approximately 3 to 4 log higher cecal Campylobacter concentration than birds challenged with C. jejuni cultured adherent to agar. Using 2 cell lines (INT 407 and DF1), virulence of C. jejuni cultured in broth versus adherent to agar also was evaluated by challenging monolayers of eukaryotic cells with 1 of 3 treatments: 1) 10(5) cfu.mL(-1) of C. jejuni cultured in broth, 2) 10(5) cfu.mL(-1) of C. jejuni cultured adherent to agar, or 3) no C. jejuni (negative control). The virulence study also showed differences of C. jejuni cultured in broth or agar in attachment and invasion abilities to tissue culture cells, but differences were not as consistent as with the chick colonization study. This study indicates that phenotype may play a role in colonization of chickens and virulence by C. jejuni.

Determination of toxicity of Campylobacter jejuni isolated from humans and from poultry carcasses acquired at various stages of production

AIM

The research focused on the determination of the toxicity variation associated with Campylobacter jejuni isolated from humans and chickens.

METHODS AND RESULTS

Campylobacter jejuni isolates were obtained from chicken carcasses and from humans exhibiting symptoms of campylobacteriosis. Using HeLa cells as the in vitro model, toxicity was determined for each isolate. The mean toxicity level of the chicken isolates was significantly lower than that of the human isolates (P < 0.001). There was a wide range of toxicity in C. jejuni isolated from chickens and the percentage of isolates exhibiting low toxicity remaining relatively constant. All C. jejuni isolates from humans possessed either medium or high levels of toxicity.

CONCLUSIONS

All wildtype C. jejuni isolates obtained from poultry carcasses may not be equally important as a human foodborne pathogen.

SIGNIFICANCE AND IMPACT OF STUDY

Campylobacter jejuni remains a primary foodborne pathogen and increased efforts are needed to determine the impact of wildtype isolates in causing human illness. The present research indicates that all isolates may not be equally important in regards to disease potential. The information found should be included in efforts to develop C. jejuni detection, control and infection modelling.

Detection of Campylobacter jejuni in poultry samples using an enzyme-linked immunoassay coupled with an enzyme electrode

An enzyme-linked immunoassay coupled with a tyrosinase modified enzyme electrode was used for rapid detection of Campylobacter jejuni. The immunomagnetic separation (IMS) method was investigated to achieve optimal isolation of C. jejuni cells. Eight types of beads with three different sizes and function groups were coated with anti-C. jejuni to isolate C. jejuni from the sample solution. Bead size and coating methods were found to be major factors that influenced the capture efficacy. Streptavidin-labeled beads (2.8 microm) provided the greatest capture ability. Three blocking reagents were tested to minimize non-specific binding. Bovine serum albumin (BSA) showed the best blocking capability. Two IMS formats were tested. Competitive immunoassay cut the detection time to 1.5 h, but the detection limit was relatively high (10(6) CFU/ml). This system was evaluated using C. jejuni pure culture and poultry samples inoculated with C. jejuni. This detection method for C. jejuni could be completed within 2.5 h and had a detection limit of 2.1 x 10(4) CFU/ml. No significant difference was found between pure culture samples and poultry samples (P>0.01). A linear relationship was found between C. jejuni cell numbers and the peak current ratio in a range of 10(2)-10(7) CFU/ml (R(2)=0.94).

Cloning and function of the rat colonic epithelial K+ channel KVLQT1

KVLQT1 (KCNQ1) is a voltage-gated K+ channel essential for repolarization of the heart action potential that is defective in cardiac arrhythmia. The channel is inhibited by the chromanol 293B, a compound that blocks cAMP-dependent electrolyte secretion in rat and human colon, therefore suggesting expression of a similar type of K+ channel in the colonic epithelium. We now report cloning and expression of KVLQT1 from rat colon. Overlapping clones identified by cDNA-library screening were combined to a full length cDNA that shares high sequence homology to KVLQT1 cloned from other species. RT-PCR analysis of rat colonic musoca demonstrated expression of KVLQT1 in crypt cells and surface epithelium. Expression of rKVLQT1 in Xenopus oocytes induced a typical delayed activated K+ current, that was further activated by increase of intracellular cAMP but not Ca2+ and that was blocked by the chromanol 293B. The same compound blocked a basolateral cAMP-activated K+ conductance in the colonic mucosal epithelium and inhibited whole cell K+ currents in patch-clamp experiments on isolated colonic crypts. We conclude that KVLQT1 is forming an important component of the basolateral cAMP-activated K+ conductance in the colonic epithelium and plays a crucial role in diseases like secretory diarrhea and cystic fibrosis.

Rapid detection of Salmonella typhimurium in chicken carcass wash water using an immunoelectrochemical method

An immunoelectrochemical method coupled with immunomagnetic separation was developed for rapid detection of Salmonella Typhimurium in chicken carcass wash water. Samples of chicken carcass wash water were inoculated with Salmonella Typhimurium at different cell numbers. Possible nonspecified inhibitors in the wash water were minimized by filtration and centrifugation. An approximately 9.4% loss of Salmonella cells was found after filtration (P < 0.01). The samples were mixed with anti-Salmonella-coated magnetic beads (ASCMB) and alkaline phosphatase-labeled anti-Salmonella (APLAS) to form ASCMB-Salmonella-APLAS conjugates. The conjugates were separated from the solution using a magnetic separator and then incubated with phenylphosphate substrate to produce phenol. The number of Salmonella was determined by measuring the phenol concentration using an amperometric tyrosinase carbon paste electrode in a flow injection analysis system. Under optimized parameters (1 mM MgCl2, 0.2 microg/ml APLAS, and 1 mM phenylphosphate in pH 7.0 Tris buffer solution), Salmonella Typhimurium in chicken carcass wash water could be identified and enumerated within 2.5 h with a detection limit of 5 x 10(3) CFU/ml. A linear relationship on a log-log scale was found between Salmonella cell number and the peak current ratio for Salmonella concentrations ranging from 10(3) to 10(7) CFU/ml (R2 = 0.963). The peak currents of multibacteria samples, containing Salmonella Typhimurium, Listeria monocytogenes, and Campylobacter jejuni, were not significantly different from Salmonella-only samples (P > 0.01).

High sensitivity ELISA determination of taxol in various human biological fluids

Taxol (paclitaxel)--the natural product isolated from Pacific yew (Taxus brevifolia)--is a novel agent with high activity in the treatment of patients with several malignant tumors including those resistant to other cytotoxic drugs. The therapeutic index of this promising anticancer drug could be further increased by the exploration of its pharmacokinetic pharmacodynamic relationship in cancer patients. Since taxol is highly protein bound, a very specific and highly sensitive analytical method is required in order to determine free, protein unbound and biologically active taxol species in human physiological fluids: plasma; plasma ultrafiltrate; and salivary fluids. In order to accomplish this, a new indirect competitive enzyme-linked immunosorbent assay (ELISA), for quantitating such a low bioactive taxol concentration level, has been developed in our laboratories. This method uses taxol competitive inhibition of mouse anti-taxol antibodies binding to the solid phase coated antigen 7-succinyltaxol-bovine serum albumin. This indicates recognition of the active taxol in the solution phase, where a diluted horseradish peroxidase labeled goat anti-mouse enzyme conjugate is used. While employing this technique, after systematic optimization of the experimental conditions, we are able to detect the anticipated taxol in plasma ultrafiltrate and salivary fluids at the concentration level of subpicogram per milliliter. The working range of the assay is approximately five orders in magnitude, i.e. from pg ml(-1) to 100 ng ml(-1). The clinical part of this study verified the working range of the ELISA method using samples of physiological fluids from a cancer patient treated with 3 h intravenous (i.v.) infusion of this drug. Our results of taxol determination in plasma, plasma ultrafiltrate and saliva demonstrate the applicability of the newly developed ELISA method for further pharmacokinetic studies of free, biologically active taxol species in cancer patients.

Plasma analysis of alpha-difluoromethylornithine using pre-column derivatization with naphthalene-2,3-dicarboxaldehyde/CN and multidimensional chromatography

A procedure for the plasma analysis of alpha-difluoromethylornithine (DFMO) has been developed that utilizes pre-column derivatization with naphthalene-2,3-dicarboxaldehyde/cyanide (NDA/CN) in pH 9.2 borate buffer. Selective derivatization of delta-amine of DFMO followed by quenching of the reaction results in the formation of a cyanobenz [f] isoindole (CBI) derivative that is stable for 24 h. Plasma was prepared for derivatization by a single step procedure which resulted in an ultrafiltrate compatible with derivatization and analysis. The DFMO derivative (CBI-DFMO) was separated from plasma interferences by multidimensional chromatography with an analysis time of 28 min. The response for DFMO in plasma was linear over the range of 2.1 x 10(-8) 2.1 x 10(-6) M after derivatization. This procedure encompasses a useful linear range and offers the advantages of minimal sample preparation and production of a stable fluorophor.

Use of antimicrobial spray applied with an inside-outside birdwasher to reduce bacterial contamination on prechilled chicken carcasses

Antimicrobial sprays applied using a modified inside-outside birdwasher to reduce Salmonella typhimurium and total aerobic bacteria on prechilled chicken carcasses were evaluated in a poultry processing pilot plant. Four chemicals, including trisodium phosphate (TSP, 10%), lactic acid (LAC, 2%), cetylpyridinium chloride (CPC, 0.5%), and sodium bisulfate (SBS, 5%) were selected to be tested as antimicrobial agents. Each chicken carcass was inoculated by spraying the outside and inside of each carcass with S. typhimurium at 10(5) CFU per carcass. The inoculated carcasses then were passed through the birdwasher and sprayed with selected chemicals at 35 degrees C at a pressure of 413 kPa for 17 s. After a 60-s setting time on a shackle line, the carcasses were sprayed with tap water to rinse off chemical residue. All the chemical treatments reduced Salmonella on the chicken carcasses by approximately 2 log10 CFU per carcass. Total aerobes on the chicken carcasses, however, were reduced by 2.16, 1.66, 1.03, and 0.74 log10 CFU per carcass after spraying with 0.5% CPC, 5% SBS, 2% LAC, or 10% TSP, respectively. Spray treatments of both SBS and LAC caused slight discoloration in part of the chicken skin. The most effective antimicrobial spray treatment for reducing both Salmonella and total aerobes on prechilled chicken carcasses was 0.5% CPC.

Hydrolysis of the prodrug, 2',3',5'-triacetyl-6-azauridine

PURPOSE

The purposes were to study the kinetics of hydrolysis of 2',3',5'-triacetyl-6-azauridine (1) in aqueous solution (mu = 0.5) and to identify the main intermediates and products of the reaction.

METHODS

A stability indicating isocratic LC assay was used to study the rate of degradation of 1. A gradient LC assay was used to study the time courses of the degradants. The products of hydrolysis were isolated by preparative liquid chromatography and identified by 1H-NMR and CI-MS. The pKa value was obtained by potentiometric titration.

RESULTS

At 36.8 degrees C, the pH-rate profile of 1 in water was adequately described by a four-term rate equation. The intermediates were identified as the primary and secondary di-acetates, and the primary and secondary mono-acetates. The final product was 6-azauridine.

CONCLUSIONS

A simplified kinetic scheme could be used to describe the concentration-time profiles of 1, the intermediates and the final product.

Evaluation of merbarone (NSC 336628) in disseminated malignant melanoma. A Southwest Oncology Group study

Merbarone, NSC 336628, is an investigational anticancer drug with activity against experimental animal tumors including melanoma. This paper presents results of a Phase II clinical study of merbarone in patients with biopsy proven stage IV malignant melanoma without prior chemotherapy and with no evidence of CNS involvement. Thirty-five patients with median age 58 (range 27-81), with performance status 0-2 were treated with merbarone 1000 mg/m2/day for five days by intravenous continuous infusion repeated every 3 weeks. All patients (21 males and 14 females) were evaluable for toxicity. Two patients were not evaluable for response having been removed from protocol treatment due to toxicity and received other treatment during the first course of chemotherapy. Among the evaluable patients there was one complete response in a supraclavicular lymph node lasting four months and one partial liver response lasting three months. The remaining thirty-one patients were non-responders. Of these one had a stable disease lasting 21 months. The overall objective response rate was 6% (2/35) with a 95% confidence interval of 1%-19%. Twenty-six of the 35 patients have died. The estimated median survival of the entire group was 9 months with a 95% confidence interval six to eleven months. Renal toxicity was dose-limiting and manifested as increasing serum creatinine (54% of patients), proteinuria (51%) and hematuria (9%). One patient experienced grade 4 creatinine increase, proteinuria and acute renal failure. Other toxicities included nausea (71%), vomiting (51%0, malaise (23%), weakness (20%), alopecia (17%), diarrhea (17), anorexia (14%) transaminase (SGOT, SGPT) increase (14%), constipation (14%), alkaline phosphatase or 5'nucleotidase increase (9%), and fever (9%). Hematologic toxicity (granulocytopenia, leukopenia, and anemia) was generally mild and infrequent (29%, only one patient had grade 4 granulocytopenia). Overall 9 patients (26%) had at least one grade 3 toxicity. We conclude that merbarone at this dose and schedule has detectable but minimal activity in the treatment of metastatic malignant melanoma and given the significant renal toxicity this schedule does not merit further evaluation in this disease.

Pharmacokinetic studies of alpha-difluoromethylornithine in rabbits using an enzyme-linked immunosorbent assay

Using an inhibition immunoassay, the pharmacokinetics of DFMO have been evaluated. After intravenous infusion, DFMO concentration in serum is observed to reach a maximum after 2-3 h followed by a decrease. This profile is consistent with the formation of a covalent adduct between DFMO and the enzyme which it irreversibly inhibits. The adduct was isolated by immunoaffinity chromatography.

Automated analytical systems for drug development studies. I--A system for the determination of drug stability

An automated system consisting of a pH-stat, microdialysis sampling and a liquid chromatograph was assembled to measure the rate of rapid chemical reactions. 2',3',5'-Triacetyl-6-azauridine was used as a model compound to validate the performance of the automated system. Buffer catalysis was minimized by using a non-catalytic concentration of borate buffer along with a pH-stat to maintain the pH during the kinetic run. The microdialysis sampling technique permitted sample quenching and buffering of the solutions to a pH compatible with the LC column materials. The combination of microdialysis sampling and rapid LC analysis allowed reactions with a half-life of approximately 1 min to be sampled every 30 s. The rates of hydrolysis of the drug, measured at different conditions of temperature (37-70 degrees C) and pH (9.0-10.5) using the automated system, compared well with the previously determined values.

Evaluation of amonafide in disseminated malignant melanoma. A Southwest Oncology Group study

Amonafide (AMF), NSC 308847 is an investigational anticancer drug acting as a DNA intercalating agent. This paper presents results of a phase II clinical study of AMF in disseminated malignant melanoma. Twenty patients, eleven males and nine females, with biopsy proven malignant melanoma, performance status 0-2; median age 59 (range 29-74), and no previous chemotherapy, were treated with AMF 300 mg/m2/day by 60 min i.v. infusion for five days repeated every three weeks. Fifteen patients had lung (9 patients) and/or liver (8 patients) involvement. None had known brain metastasis at entry. All 20 patients were evaluated for response and toxicity. Six patients had stable disease and fourteen had increasing disease. With 0/20 responses, the upper 95% confidence limit for the response rate was 14%. The median survival time was 5.7 months. Hematologic toxicity was dose limiting with the incidence of leucopenia 45% and thrombocytopenia 20%. The nonhematologic toxicities included nausea and vomiting (60%), alopecia (20%), headaches (15%), diarrhea (10%), and phlebitis (10%). We conclude that AMF administered at this dose and schedule is not active in the treatment of patients with malignant melanoma, previously untreated with chemotherapy.

Degradation of dacarbazine in aqueous solution

The effects of initial concentration (0.05-5.0 mg ml-1, 2.5 x 10(-4)-0.025 M) (pH 1-13), buffer concentration (0.01-0.075 M), light, antioxidants and co-solvents on the degradation of dacarbazine in aqueous solution were investigated at 37 degrees C. Liquid chromatography was used to monitor the degradation of dacarbazine as well as the appearance of degradation products. The kinetics of hydrolysis of dacarbazine in the dark were pseudo first-order and independent of the initial concentration of the drug. The degradation of dacarbazine was accelerated by light and at low concentration proceeded by pseudo zero-order kinetics. The pH-rate profiles showed that both the photolytic and the hydrolytic reactions were dependent on the ionization state of the molecule. The main degradation product of both hydrolysis and photolysis was detected by liquid chromatography and confirmed by mass spectrometry to be 2-azahypoxanthine.

Development of a simplified method for subclass isotyping and screening monoclonal antibodies

A simplified dot-blot procedure for screening and subclass isotyping of monoclonal antibodies is described in which only 0.5-50 ng of antigen and 1 microliter of antibody are needed to perform the test. The results on the nitrocellulose membrane can be stored indefinitely for future reference. This method is less expensive, uses smaller quantities of antigen and antibody, and is faster than presently used enzyme-linked immunosorbent assay techniques or other dot-blot methods. Monoclonal antibodies against Mycoplasma gallisepticum were screened and isotyped using this technique.

Phase I evaluation of spirogermanium and 5-fluorouracil in colorectal carcinoma

We have conducted a phase I study to evaluate the toxicity and tolerance of a 5 day continuous infusion of spirogermanium and 5-fluorouracil, (5-FU). The 5-FU was administered via a peripheral vein at 1000 mg/M2/day for 5 days by continuous infusion. Simultaneously, spirogermanium was administered via an indwelling central venous catheter by continuous infusion for 5 days starting at 50 mg/M2/day and escalating to 250 mg/M2/day. Sixteen patients received a total of 54.5 courses of therapy. The most common and severe toxicity was neurotoxicity. Mild to moderate gastrointestinal toxicity also occurred. No significant hematologic toxicity occurred. Two partial responses occurred lasting 11 and 20.5 months, both at the 100 mg/M2/day level of spirogermanium. The recommended phase II dosages are 5-FU 1000 mg/M2/day and spirogermanium 200 mg/M2/day by 5 day continuous infusion with escalation of the spirogermanium in selected individuals. Patients on long term therapy should have close neurologic evaluation and follow up. Consideration should also be given to evaluating a group of patients at the 100 mg/M2/day level of spirogermanium due to the responses seen at this level.

Elimination of mycoplasmal plate agglutination cross-reactions in sera from chickens inoculated with infectious bursal disease viruses

Sera from chickens inoculated with various challenge infectious bursal disease viruses or infectious bursal disease vaccines were found to cross-react in the Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) serum plate agglutination (SPA) tests. Two-fold dilutions of these cross-reacting sera with phosphate-buffered saline before retesting eliminated all non-specific agglutination in the MG and MS SPA tests. Cross-reactions were observed in the SPA test using sera from chickens inoculated with either MG or MS. Dilutions of these sera 1:2 had little effect on the number of these cross-reactions. At 1:4 serum dilutions, however, the number of cross-reactions between MG and MS was reduced. At 1:8 dilution of test sera, cross-reactions between MG and MS were further reduced. Some reduction in specific MG and MS SPA reactions, however, also occurred at the 1:8 dilution of sera with some of the plate antigen.

Stereoselective pharmacokinetics and metabolism of the enantiomers of cyclophosphamide. Preliminary results in humans and rabbits

[R(+),S(-)]-Cyclophosphamide [(R,S)-CP] is an anticancer drug, containing a chiral phosphorous atom, which is prepared and used clinically as the racemic mixture. A new high-performance liquid chromatographic assay suitable for pharmacokinetic studies of CP enantiomers in plasma has been reported recently by this laboratory (Reid et al., Anal Chem 61: 441-446, 1989). Briefly, the assay involves ethyl acetate extraction of CP enantiomers from plasma followed by derivatization to diastereomers in a two-step process utilizing chloral and (+)-naproxen acid chloride. Chromatographic analysis was performed on a reversed phase (ODS) column with detection at 232 nm. In the present study, preliminary results on the applicability of this assay to pharmacokinetic studies are presented. Several rabbits were used to compare the influence of i.p., i.v., and oral routes of administration on the stereoselective disposition of (R,S)-CP. Following i.p. administration, S-CP was cleared faster than R-CP. Following oral administration, only R-CP was detectable in plasma, while i.v. administration resulted in minor or no stereoselective disposition. These results indicated that there was a marked stereoselective metabolism of the S-CP enantiomer, with the i.p. and oral routes producing the greatest differences due to first-pass metabolism. Incubation of rabbit-liver microsomes with (R,S)-CP demonstrated that the monooxygenase system can exhibit marked stereoselectivity in its metabolism of CP. The ratio of R-CP to S-CP in the incubation medium increased during the incubation period from 1:1 initially to 4.5:1 after 60 min. The results from the experiments with rabbits indicate that the first-pass metabolism of this drug is highly stereoselective; in contrast, cancer patients who had received (R,S)-CP as an i.v. infusion showed no stereoselectivity in the elimination of the enantiomers. Pharmacokinetic studies with cancer patients, receiving (R,S)-CP as an oral dose, are in progress in order to determine if stereoselective first-pass metabolism of this drug also occurs in humans.

Pyridoxine therapy for palmar-plantar erythrodysesthesia associated with continuous 5-fluorouracil infusion

The limiting toxicity of low dose continuous infusion 5-fluorouracil (200-300 mg/m2/day) is often palmar-plantar erythrodysesthesia (PPE). PPE developed in 16/25 patients (exact 95% confidence interval of 42%-82%) with metastatic colon cancer enrolled in a phase II trial. In this trial, 5-FU was given continuously at a dose of 200 mg/m2/day until toxicity or progressive disease forced discontinuation. The first signs of the syndrome developed at a median of 2 months following infusion initiation and, unless treatment was interrupted, became progressively worse. The incidence of moderate to severe PPE was 71% in the 14 previously untreated patients (exact 95% confidence intervals of 42-92%). Seventy-eight percent of the responders in the no prior treatment group developed PPE. The incidence of moderate to severe PPE was only 27% in the 11 previously treated patients (exact 95% confidence intervals of 6-61%). The higher incidence of PPE in the previously untreated patients probably resulted from a longer total infusion time (median = 7.3 months) than the previously treated (median = 4.5 months). The longer infusion time in turn was a result of the higher response rates (64 vs 18%) in the previously untreated versus treated groups. Five previously untreated patients who developed PPE received 50 or 150 mg of pyridoxine/day when moderate PPE changes were noted. Reversal of PPE without interruption of the 5-FU was seen in 4/5 patients. Four of these patients who received pyridoxine had responded to 5-FU treatment. No adverse affect of pyridoxine on clinical response was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of 5-fluorouracil in plasma by precolumn derivatization with 4-bromomethyl-7-methoxycoumarin, followed by multi-dimensional high-performance liquid chromatography

An assay for 5-fluorouracil (5-FU) has been developed that utilizes a double extraction with ethyl acetate, followed by precolumn derivatization with 4-bromo-methyl-7-methoxycoumarin. The reaction mixture was quenched with 5% acetic acid, extracted with hexane, and analyzed by multi-dimensional high-performance liquid chromatography. Derivatized 5-FU was injected into a cyanopropyl column and a heart cut containing the analyte was then switched to an octadecyl column and quantitated by fluorescence detection. The assay had a limit of detection of 0.5 ng 5-FU/ml plasma and was linear to 20 micrograms/ml. It was shown to be free of interferences from the other anticancer agents commonly used in combination with 5-FU. This assay should have the sensitivity needed to measure the low levels that occur after low-dose, continuous infusion of 5-FU.

High-performance liquid chromatography of 5-fluorouracil after derivatization with 4-bromomethyl-7-methoxycoumarin. Characterization of the derivative and the use of column switching for the improvement of resolution and the enhancement of sensitivity

The derivatization of 5-fluorouracil with 4-bromomethyl-7-methoxycoumarin has been reported previously; however, the structure of the derivative was not confirmed. The synthesis and purification of the 5-FU derivative is described along with the spectroscopic (MS and NMR) determination that it is labelled at both heterocyclic nitrogens as expected. A column switching HPLC system is also presented which consists of primary separation on a cyanopropyl column followed by a final separation on an ODS column with fluorescence detection. This system removes all interferences from the derivatization system and has a limit of detection for the pure derivative of less than 50 fmol (injection volume = 100 microliters).

Changes in serum copper and zinc during treatment with anticancer drugs interfering with pyridoxal phosphate

Hexamethylmelamine, pentamethylmelamine and procarbazine are anticancer drugs known to interfere with pyridoxal phosphate. This paper presents results on copper and zinc serum levels during the treatment with each of these drugs used as single agents. Six NZW rabbits weighing 2.7-4.5 kg were used in these experiments. Hexamethylmelamine and procarbazine were administered by gastric gavage and pentamethylmelamine by intravenous route at the daily doses of 100 mg, 30 mg and 50 mg/kg of body weight respectively for up to four days. Blood samples were collected in metal free tubes at fasting state before and during the treatment. Student's paired t-test was used for statistical analysis. The pretreatment serum copper concentration significantly (p = 0.05) increased and conversely the serum zinc concentration significantly (p = 0.05) decreased during each drug treatment. Consequently the copper/zinc ration significantly increased from 0.32, 0.33 and 0.27 to 1.16, 0.63 and 1.13 for hexamethylmelamine, pentamethylmelamine and procarbazine respectively. These results indicate, that daily administration of three anticancer drugs interfering with pyridoxal phosphate causes changes in serum copper and zinc levels with inversed relationship between both changes.

Phase I trial and pharmacokinetic study of intravenous and oral alpha-difluoromethylornithine

Eflornithine-HCl (alpha-difluoromethylornithine or DFMO), an irreversible inhibitor of ornithine decarboxylase, blocks polyamine synthesis and has demonstrated antitumor activity in cell culture and animal tumor models. This phase I study was designed to determine and compare toxicity and the maximally tolerated dose of a 4-day course of DFMO given to patients in oral, continuous intravenous infusion or pulse intravenous infusion forms. Twenty-four patients were entered into this study: 8 received intravenous pulse drug, 10 intravenous continuous infusion of drug, and 6 oral DFMO. The most frequent toxicity was nausea and vomiting which occurred in 9 courses of oral drug. Only two patients receiving intravenous DFMO had nausea and vomiting. Clinically significant thrombocytopenia and audiometric abnormalities were not encountered in contrast to previous experience with 28-day courses of oral DFMO. The maximally tolerated dose of a four-day course of oral DFMO was 3.75 gm/M2 every 6 hours. The maximally tolerated dose of intravenous pulse and continuous infusion DFMO was not attained. Pharmacokinetic studies demonstrated that the intravenous schedules achieved higher plasma levels of DFMO than those previously obtained with chronic oral dosing.

Phase I evaluation of chlorozotocin (NSC-178248): weekly schedule

A phase I trial of chlorozotocin was completed for a weekly times four dose schedule repeated every 8 weeks. Thrombocytopenia was the acute dose limiting toxicity. Nausea and vomiting were moderate to severe and dose related. Two cases of possible drug related irreversible nephrotoxicity were seen. Transient elevations of serum creatinine and mild proteinuria were noted. Also, transient elevations in SGOT were observed. One patient with a carcinoid tumor had a 60% reduction in his 5HIAA level after one course of therapy. The recommended dose for phase II clinical studies of chlorozotocin is 40 mg/m2 IV weekly for four weeks, repeated every 8 weeks.

A phase II study of PALA (NSC 224131) in patients with advanced ovarian carcinoma. A Gynecologic Oncology Group study

Pala, 5G /M2 i.v. every 3 weeks was given to 32 evaluable patients with ovarian carcinoma (31 previously treated). No complete or partial responses were noted. Ten patients had stable disease for a median progression-free interval of 4.7+ months, while the remainder had progression of disease from the start of therapy. The major toxicity was dermatologic, and five patients had severe skin rash with desquamation or ulceration. There was no substantial hematologic or gastrointestinal toxicity. PALA displays no useful activity in previously-treated patients with ovarian cancer.

An individualized plastic intraoral device for the collection of human parotid saliva

A new individualized, non-invasive device for the collection of parotid saliva is described which offers the following advantages: automatic placement in the proper position for saliva collection by patients without the help of a technician, lack of deadspace, lack of salivary leakage around the device, elimination of cross contamination between patients, and unlimited re-use. Because of its simplicity, it is an ideal device for routine collection of parotid saliva samples in therapeutic drug monitoring, biochemical monitoring of exposure to toxic materials, and detection of secretory component deficiencies of immune system disorders.