Microbiological methods for testing disinfectant efficiency on Pseudomonas biofilm.

Biofilms of the Gram-negative bacteria Pseudomonas aeruginosa and Pseudomonas fragi were grown on stainless steel surfaces (AISI 304, 2B) for 4 days in slime broth. These biofilms were treated with four commercial disinfectants. The disinfectants were alcohol-based, tenside-based, peroxide-based and chlorine-based products, covering most disinfectant types used in the food industry. The effects of the disinfectants on the bacterial cells were first investigated in suspension using the permeabilisation test, which is based on fluorescence assessment of hydrophobic 1-N-phenyl-naphtylamine (NPN). The surfaces covered with disinfectant-treated biofilms were investigated using conventional cultivation, impedimetry and epifluorescence microscopy in combination with image analysis of preparations stained with the DNA-stain acridine orange and with the metabolic indicator system CTC-DAPI. The results showed that the tenside-based and peroxide-based disinfectants permeabilised the cells in suspension. The overall biofilm results showed that of the agents tested, the peroxide-based and chlorine-based disinfectants acted most effectively on cells in biofilms.

Validation of the microbiological methods hygicult dipslide, contact plate, and swabbing in surface hygiene control: a Nordic collaborative study.

A collaborative study on total aerobic bacterial count was conducted to validate the Hygicult TPC dipslide against contact plates and swabbing, using stainless-steel surfaces artificially contaminated with different microbes at various levels. Twelve laboratories took part in the validation procedure. The total number of collaborative samples was 108. The microbial level in each sample was assessed in triplicate using the 3 above-mentioned methods under 3 different incubation conditions (at 25 +/- 1 degrees C for 48 and 72 h and at 30 +/- 1 degrees C for 48 h). Surface sampling methods detached 25-30% at the lowest (theoretical yield, 1.4 cfu/cm2), 18-20% at the middle (theoretical yield, 10.7 cfu/cm2), and 16-21% at the highest (theoretical yield, 43.6 cfu/cm2) levels of microbes from the test surfaces. The percentage of acceptable results after removing outliers was 89%. Repeatability standard deviations ranged from 27.2 to 74.6% and reproducibility standard deviations ranged from 42.1 to 97.5%. There were no significant differences between results obtained at different incubation temperatures (25 and 30 degrees C) or incubation times (48 and 72 h) for all 3 methods. The Hygicult TPC dipslide, contact plate, and swabbing methods gave similar results at all 3 microbial levels tested: 0.35-0.43 cfu/cm2 at the lowest level, 1.9-2.2 cfu/cm2 at the middle level, and 7.1-9.1 cfu/cm2 at the highest level.

Microbial testing methods for detection of residual cleaning agents and disinfectants-prevention of ATP bioluminescence measurement errors in the food industry.

The ATP luminescence measurement is based on the presence of an enzymatic reaction and may significantly be affected by cleaning agents and disinfectants. In addition, disinfectants can also reduce the activity of the luciferase enzyme and also act as ATP-releasing agents. The agents disrupt the cell walls but preserve ATP in measurable form, and therefore correlation with culture methods can be poor. Therefore, if a rapid method is used to detect ATP, a control must be used for reliable results. The possible effect of disinfectants can be eliminated with a rapid test to minimize sources of error. In the present study a microbiological residue testing method that is nonspecific for residues was developed. The effects of a total of 38 commercial cleaning agents and disinfectants of various types were assessed using two microbiological methods, the Vibrio fischeri photobacteria test and Micrococcus luteus inhibition zone technique. The results show that the V. fischeri photobacteria test is very sensitive. This test can therefore be used for testing cleaning agent residues on surfaces in very small amounts. A small study was also carried out in a food factory to show applicability in processing facilities. The study showed, that a need for this type of method exists in food processing.

Performance evaluation of disinfectant formulations using poloxamer-hydrogel biofilm-constructs.

Poloxamer F127 is a di-block co-polymer of polyoxyethylene and polyoxypropylene. Aqueous solutions show thermo-reversible gelation, being liquid at temperatures < 15 degrees C and robust gels at temperatures > 15 degrees C. Chilled poloxamer solutions (30% w/v) were inoculated with approximately 10(4-5) cfu ml-1 of stationary phase cultures of Pseudomonas aeruginosa, Ps. fluorescens, Pantoea agglomerans, Micrococcus luteus, Staphylococcus epidermidis, Bacillus subtilis or Listeria innocua. Drops (200 microliters) of the inoculated poloxamers were placed on stainless steel coupons held in Petri dishes containing moistened cotton wool and incubated at 30 degrees C for 5 h. All strains grew well giving between 10(6-7) cfu ml-1 at 5-6 h. The cultured gels were readily applied to tests of biocide effectiveness as the stainless steel coupons could be removed and flooded with biocide solution for fixed exposure times. Provided that the temperature of the biocide solutions was > 15 degrees C, the integrity of the gels could be maintained during exposure. After exposure, the gels and their supports were removed to separate tubes containing neutralizer solution (< 15 degrees C). The gels rapidly dispersed within 5 min to ensure a complete recovery of the sample population. Biofilm-constructs and cell suspensions (10(7) cfu ml-1) were exposed to four commercial disinfectant formulations, based on hypochlorite, alcohol, hydrogen peroxide and a tenside, at recommended use levels. Cell suspensions, in the presence of bovine serum albumen (BSA; 0.03% w/v), were subject to a > 5-log kill within 5 min while the killing effected against the biofilm-constructs varied between 0.4 and 2-log reductions. The results indicate a high degree of reproducibility between replicate samples, with patterns of susceptibility varying both as a function of organism, biocide type and concentration. The experiments strongly support the view that poloxamer-constructs are suitable for application in trials and testing of disinfectant formulations.

Diffuse testicular microlithiasis associated with intratubular germ cell neoplasia and seminoma.

Testicular microlithiasis is an uncommon condition in which multiple calcifications develop in the seminiferous tubules. Sonography demonstrates a typical pattern of diffuse, hyperechoic specks. This condition has been associated with premalignant and malignant changes of the testicle. We present a case of intratubular germ cell neoplasia and a microscopic focus of seminoma found in a patient with isolated testicular microlithiasis and no focal mass. Physicians should be more aware of testicular microlithiasis, and heightened surveillance is recommended to identify progression to tumor formation.

A microbiological screening method for the indication of irradiation of frozen poultry meat.

A microbiological screening method for the detection of irradiation of frozen poultry meat was developed on the basis of the combined use of total cell count by the direct epifluorescent filter technique (DEFT) and viable cell count by the aerobic plate count method (APC). Samples of ground, deboned poultry leg were irradiated or not with dose levels of 3, 5 and 7 kGy using an electron beam accelerator. All samples were frozen before the irradiation treatment. The average values of the differences between DEFT and APC counts in control samples and those irradiated with doses of 3, 5 and 7 kGy were 1.14 log units for control samples, and 3.16, 3.68 and 3.79 log units for the irradiated samples. A difference of at least 2 log units can therefore be considered as a limit value indicating probable irradiation treatment necessitating further investigations.

Microbiological screening method for indication of irradiation of spices and herbs: a BCR collaborative study.

A BCR1 collaborative study was conducted with a microbiological screening method based on the combined use of the direct epifluorescent filter technique (DEFT) and the conventional aerobic plate count method (APC) for detection of irradiation of spices and herbs. Collaborative samples of whole allspice, whole and powdered black peppers, whole white pepper, paprika powder, cut basil, cut marjoram, and crushed cardamom irradiated with doses of 0, 5, and 10 kGy were analyzed by 8 laboratories. The total number of the collaborative samples, with arbitrarily labeled codes, was 192. The percentage of acceptable results was 95.5%. The identification of irradiated from nonirradiated spices and herbs was analyzed statistically by using explorative techniques. The average values of the differences between DEFT and APC in samples irradiated with doses of 5 and 10 kGy were 5.1 and 6.1 logarithmic units, respectively. The differences between DEFT and APC generally increased to at least 3.5 logarithmic units, whereas the difference in the case of unirradiated spices was insignificant. However, conclusive evidence of irradiation relies on the knowledge that the sample was not fumigated or heat treated. The reproducibility relative standard deviations for the differences were 12.3, 19.9, and 20.7% with the doses of 10 and 5 kGy and for unirradiated samples, respectively, indicating acceptable variabilities among laboratories.

Intraarterial iododeoxyuridine infusion combined with irradiation. A pilot study.

The halogenated pyrimidine, iododeoxyuridine (IUdR), enhances cytotoxicity of ionizing irradiation experimentally. Continuous intraarterial infusion of IUdR was combined with irradiation to maximize drug concentration in tumor and reduce potential systemic toxicity. Percutaneous tumor-specific artery catheterization was utilized in five patients, with delivery of IUdR (20 mg/kg/day) by continuous infusion 5 days prior to irradiation treatments and continued for 10-14 days. Infusion vessels included the internal mammary, the internal iliac, the renal, the common femoral, and the bronchial arteries. Conventional radiotherapy fields, fractionation, and total doses were utilized, and therapy was well tolerated. Low-grade leukopenia and thrombocytopenia was observed several weeks following infusion. A clinically nonsignificant skin reaction was observed within the irradiation fields 2-3 weeks after initiation of irradiation in several patients. No alopecia or stomatitis was observed. This study minimizes initial hepatic dehalogenation of IUdR when given by intraarterial administration. Two patients have been free of disease for over 20 years, with no long-term toxicity from IUdR therapy.

Phase I trial of hepatic artery infusion of 5-iodo-2'-deoxyuridine and 5-fluorouracil in patients with advanced hepatic malignancy: biochemically based combination chemotherapy.

Eighteen patients with hepatic metastases primarily from colorectal carcinoma were treated on a phase I protocol employing hepatic artery infusion (HAI) of 5-fluorouracil (FUra) and 5-iodo-2'-deoxyuridine (IdUrd) via implantable infusion pump. Patients received a 14-day continuous HAI of 300 mg/day FUra. During days 8-14 of therapy, patients received IdUrd as a separate 3-h HAI daily x 7. Treatment cycles were repeated every 28 days. IdUrd was escalated from 0.1 to 2.86 mg/kg/day x 7. Myelosuppression and stomatitis were mild and not dose limiting. Hepatotoxicity was dose limiting and similar to that reported for 5-fluoro-2'deoxyuridine alone administered as a 14-day infusion every month. One patient developed a clinical picture consistent with sclerosing cholangitis and another had biopsy-proven cholestasis and triaditis. Catheter complications occurred in 7 of 18 patients. Plasma concentrations of FUra during the 7-day continuous HAI of FUra alone were consistently either undetectable or very low (less than or equal to 0.1 microM). At level 3 (1.0 mg/kg/day IdUrd) and beyond, measurable plasma concentrations of FUra, iodouracil, and IdUrd were found at the end of the daily 3-h infusion of IdUrd. The maximum tolerated dose of IdUrd as administered in this trial is 2.2 mg/kg/day x 7 and the recommended starting dose for further clinical investigation is 1.7 mg/kg/day x 7.

Combined hepatic artery 5-fluorouracil and irradiation of liver metastases. A randomized study.

The effect of hepatic irradiation (RT) after intraarterial 5-fluorouracil (5-FU) was evaluated in 37 randomized patients with colorectal adenocarcinoma hepatic metastases. Patients underwent percutaneous transbrachial artery catheterization of the hepatic artery followed by 21-day continuous 5-FU infusion (CT). Hepatic irradiation of 25.5 Gy was delivered to 19 patients 14 days after completion of infusion (CT + RT). All patients received subsequent weekly maintenance 5-FU. A 37% (seven of 19) response rate was observed in CT + RT, and a 50% response rate (nine of 18) in CT: median survival was 6 months for CT + RT, and 8 months for CT, (P = 0.106). Improved survival was observed in two subsets of patients. Tumor vascularity was graded angiographically from 0 to 4+; those patients with highest vascularity (4+) had a 20-month median survival (P = 0.0009). Patients with Grade 1, well-differentiated, histologic type had a median survival of 20 months (P = 0.0001). Four patients with both 4+ vascularity and Grade 1 histologic type had 27.5 months' median survival (P = 0.0019). Age, performance status, elevated liver function tests, previous systemic therapy, and time interval between diagnosis and entry on this study did not impact on survival (P greater than 0.05), nor did these variables eliminate the significance of vascularity and grade (P less than 0.05). Survival after intraarterial 5-FU infusion was not improved by this regimen of sequential external irradiation. Regional therapy may benefit those patients with 4+ vascular tumors and/or well-differentiated tumor grade. Future trials are needed to explore the interaction of halogenated pyrimidines with irradiation and determine whether these prognostic factors can aid in patient selection for regional therapy of hepatic metastases.

Primary anterior mediastinal malignant teratoma. A case report with long-term survival.

Primary anterior mediastinal malignant teratoma is an uncommon tumor. A 17-year-old girl presented with an advanced tumor extending parasternally. Therapy consisted of intraarterial iododeoxyuridine and irradiation followed by surgical resection after failing multidrug therapy. The patient is without evidence of disease 23 years after therapy.

Treatment of probable subclinical liver metastases and gross pancreatic carcinoma with hepatic artery 5-fluorouracil infusion and radiation therapy.

Since subclinical hepatic metastases are frequently present at time of diagnosis of pancreatic carcinoma, any meaningful effort to improve survival must include 'prophylactic' liver therapy in addition to treatment of the pancreatic primary. We report the results of a prospective, unrandomized clinical trial of a 2-week liver and pancreas infusion (by hepatic artery) of 5-fluorouracil (5-FU) and pancreatic irradiation to 50-60 Gy, combined with prophylactic irradiation of the liver with approximately 20 Gy. Of 21 evaluable patients, 17 completed therapy without excessive toxicity and had a median survival of 50 weeks. Contrary to historical controls, the liver in our series was rarely the first site of failure (6%), suggesting that the combination of hepatic artery 5-fluorouracil and 20 Gy liver radiation may suppress subclinical (microscopic) liver metastases without significant hepato-toxicity. When radiation doses to the pancreas were increased above 50 Gy there was improvement in primary tumor control, although failure in the pancreatic bed remained the most common site of failure. Future clinical investigation of this form of combined therapy for eradication of micro-metastasis in the liver, combined with more aggressive local pancreatic therapy, would seem appropriate.

Percutaneous lymph node aspiration in patients with gynecologic tumors.

Sixty-one patients with gynecologic malignancies had percutaneous transperitoneal lymph node aspiration performed by a flexible 8-inch needle guided to the nodes under monoplanar fluoroscopy. Of the patients who had malignant cells aspirated from pelvic and periaortic lymph nodes, 64% died or are alive with disease. Only 30% who had negative cytologic testing died or are alive with disease. Of the patients who had malignant cells aspirated from periaortic nodes, 69% died or are alive with disease whereas only 8% with negative cytologic testing died or are alive with disease. We believe that therapy such as extended field irradiation can be given on the basis of these results.

High Z elements in human sarcomata: assessment by multienergy CT and neutron activation analysis.

"Tumor equivalent" phantoms containing inorganic salts (KH2PO4, CH3COOK, NaCl and Kl) were scanned on an EMI 5005 body scanner at 140 kVp, 28 mA; 120 kVp, 33 mA; and 81 kVp, 42 mA. Significant signal gain for the detection of higher atomic number elements by multiple energy scanning was noted. Certain sarcomas are known to accumulate high Z elements. Accordingly, excised specimens of various histologies of human sarcomata (chondrosarcoma, liposarcoma, and malignant fibrous histiocytoma) were scanned at 140 kVp and 81 kVp. Using selected areas of interest in the computed tomographic (CT) image to direct the in vitro biopsy of various regions of excised tumors, interesting correlations between the CT number variation and the respective, high Z elemental composition variation, as determined by thermal neutron activation analysis were observed. Further investigation with phantoms and excised sarcomata at 62 kVp and 42 mA suggested that dual energy CT scanning (at 140 kVp and 62 kVp) may be a method of monitoring "effective Z" and heavy element compositional changes. The authors are also attempting to develop these same low kilovoltage techniques as a method for the noninvasive clinical monitoring of an antisarcoma chemotherapeutic agent, cis-diammineaichloroplatinum (11).

Septic endarteritis due to intra-arterial catheters for cancer chemotherapy. I. Evaluation of an outbreak. II. Risk factors, clinical features and management, III. Guidelines for prevention.

A cluster of three cases of staphylococcal septic endarteritis originating from percutaneously inserted brachial artery catheters for regional cancer chemotherapy prompted an epidemiologic and clinical study of bacteremic infections associated with this therapeutic modality. Nine cases were identified over a 3 1/2-year period (1.6% of all catheterizations), all caused by Staphylococcus aureus. The cluster followed discontinuation of hexachlorophene for scrub of the extremity prior to cannulation; phage-typing suggested the three cases were caused by the patients' own strains of Staphylococcus. These infections produced a distinctive clinical syndrome which facilitates implicating the catheter in the genesis of fever occurring in a patient receiving intra-arterial chemotherapy: early localized pain (89%) and hemorrhage (78%), and Osler's nodes distally (44%), later followed by local inflammation (78%), purulence (56%) and signs of systemic sepsis (100%) (each factor, p less than or equal to .005). Duration of cannulation did not influence susceptibility to infection. However, difficult cannulations or need for repositioning the catheter (p = .0096), prior radiation therapy (p = .033), leukopenia (p less than .05) and hypoalbuminemia (p less than .05) were all associated with septicemia. In the 25 months since implementation of specific control measures, there have been no further catheter-related septicemia in 310 catheterization (p less than .001). Guide-lines for prevention and management of these infections are provided.

Accuracy of bipedal lymphography in Hodgkin's disease.

Bipedal lymphography was used as part of the initial staging evaluation of 145 patients with Hodgkin's disease. Histologic correlation was available in 131 patients. The accuracy of interpretation was 95%. A review of other large series confirms that at least 85%-90% accuracy can be expected. Reasons for false positive and false negative interpretations are discussed.

Gastric ulceration in patients receiving intrahepatic infusion of 5-fluorouracil.

Gastric ulceration developed in eight patients during intrahpeatic arterial infusion of 5-FU. Bleeding occurred in four instances and perforation in one. In all cases the catheter tip had been dislodged and was proximal to its correct position, allowing the stomach to be directly infused with 5-FU. No duodenal ulcers were noted. All patients were symptomatic for several days before the diagnosis was made. Of 20 patients with catheter dislodgement, five had documented ulcers, three had upper gastrointestinal bleeding of undetermined etiology, eight had epigastric pain or vomiting and only four were asymptomatic. Prompt determination of catheter position is necessary in patients receiving intrahepatic arterial infusion of 5-FU if symptoms consistent with gastric ulceration occur. Gastric ulcers should be vigorously treated because of the high rate of complications in patients receiving chemotherapy.

Bipedal lymphangiography in malignancies of the uterine corpus.

Bipedal lymphangiography was performed in 116 selected patients with primary endometrial malignancy since 1970. A total of 32 were interpreted as positive and 84 as negative. Although histologic confirmation of nodal interpretation was seldom obtained, short term follow-up indicates that a positive interpretation is associated with an extremely poor prognosis. Lymphangiograms are recommended in all stage I patients except those with well differentiated histology, a small corpus, and no deep myometrial invasion. This study is also recommended for all stage II and III patients and for selected patients with stage IV disease.

Accuracy of bipedal lymphangiography in testicular tumors.

The accuracy of bipedal lymphangiography to evaluate nodal metastases in patients with testicular malignancies is discussed. A total of 108 patients were evaluated. Histologic correlation was available in 45 cases. The over-all accuracy was 89% which compares favorably with other large series.