Further Characterization of Genetically Distinct Groups of Acidovorax citrulli Strains.

Bacterial fruit blotch of cucurbits (BFB) is caused by the gram-negative bacterium Acidovorax citrulli, whose populations can be distinguished into two genetically distinct groups, I and II. Based on visual assessment of BFB severity on cucurbit seedlings and fruit after inoculation under greenhouse conditions, group I A. citrulli strains have been reported to be moderately to highly virulent on several cucurbit hosts, whereas group II strains have exhibited high virulence on watermelon but low virulence on other cucurbits. Additionally, group I strains are recovered from a range of cucurbit hosts, while group II strains are predominantly found on watermelon. The goal of this research was to develop tools to characterize and rapidly distinguish group I and II A. citrulli strains. We first sought to determine whether quantification of A. citrulli colonization of cucurbit seedling tissue reflects the differences between group I and II strains established by visual assessment of BFB symptom severity. Spray inoculation of melon seedlings with cell suspensions containing approximately 1 × 104 CFU/ml resulted in significantly higher (P = 0.01) population growth of M6 (group I; mean area under population growth curve [AUPGC] = 43.73) than that of AAC00-1 (group II; mean AUPGC = 39.33) by 10 days after inoculation. We also investigated the natural spread of bacterial cells and the resulting BFB incidence on watermelon and melon seedlings exposed to three group I and three group II A. citrulli strains under mist chamber conditions. After 5 days of exposure, the mean BFB incidence on melon seedlings exposed to representative group II A. citrulli strains was significantly lower (25 and 3.98% in experiments 1 and 2, respectively) than on melon seedlings exposed to representative group I strains (94.44 and 76.11% in experiments 1 and 2, respectively), and on watermelon seedlings exposed to representative group I and II strains (70 to 93.33%). Finally, we developed a polymerase chain reaction assay based on the putative type III secretion effector gene, Aave_2166, to rapidly distinguish group I and II A. citrulli strains. This assay will be important for future epidemiological studies on BFB.

Development of a novel instrument for assessing intentional non-adherence to official medical recommendations (iNAR-12): a sequential mixed-methods study in Serbia.

OBJECTIVES: We aimed to (1) develop a novel instrument, suitable for the general population, capturing intentional non-adherence (iNAR), consisting of non-adherence to prescribed therapy, self-medication and avoidance of seeking medical treatment; (2) differentiate it from other forms of non-adherence, for example, smoking; and (3) relate iNAR to patient-related factors, such as sociodemographics, health status and endorsement of irrational beliefs (conspiratorial thinking and superstitions) and to healthcare-related beliefs and experiences ((mis)trust and negative experiences with the healthcare system, normalisation of patient passivity). DESIGN: То generate iNAR items, we employed a focus group with medical doctors, supplemented it with a literature search and invited a public health expert to refine it further. We examined the internal structure and predictors of iNAR in an observational study. SETTING: Data were collected online using snowball sampling and social networks. PARTICIPANTS: After excluding those who failed one or more out of three attention checks, the final sample size was n=583 adult Serbian citizens, 74.4% female, mean age 39.01 years (SD=12.10). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary, planned outcome is the iNAR Questionnaire, while smoking was used for comparison purposes. RESULTS: Factor analysis yielded a one-factor solution, and the final 12-item iNAR Questionnaire had satisfactory internal reliability (alpha=0.72). Health condition and healthcare-related variables accounted for 14% of the variance of iNAR behaviours, whereas sociodemographics and irrational beliefs did not additionally contribute. CONCLUSIONS: We constructed a brief yet comprehensive measure of iNAR behaviours and related them to health and sociodemographic variables and irrational beliefs. The findings suggest that public health interventions should attempt to improve patients' experiences with the system and build trust with their healthcare practitioners rather than aim at specific demographic groups or at correcting patients' unfounded beliefs. STUDY REGISTRATION: The design and confirmatory analyses plan were preregistered (https://osf.io/pnugm).

Tracking variations in daily questionable health behaviors and their psychological roots: a preregistered experience sampling study.

People resort to various questionable health practices to preserve or regain health - they intentionally do not adhere to medical recommendations (e.g. self-medicate or modify the prescribed therapies; iNAR), or use traditional/complementary/alternative (TCAM) medicine. As retrospective reports overestimate adherence and suffer from recall and desirability bias, we tracked the variations in daily questionable health behaviors and compared them to their retrospectively reported lifetime use. We also preregistered and explored their relations to a wide set of psychological predictors - distal (personality traits and basic thinking dispositions) and proximal (different unfounded beliefs and biases grouped under the term irrational mindset). A community sample (N = 224) tracked daily engagement in iNAR and TCAM use for 14 days, resulting in 3136 data points. We observed a high rate of questionable health practices over the 14 days; daily engagement rates roughly corresponded to lifetime ones. Both iNAR and TCAM were weakly, but robustly positively related. Independent of the assessment method, an irrational mindset was the most important predictor of TCAM use. For iNAR, however, psychological predictors emerged as relevant only when assessed retrospectively. Our study offers insight into questionable health behaviors from both a within and between-person perspective and highlights the importance of their psychological roots.

The combination of the three modifications of the component separation technique in the management of complex subcostal abdominal wall hernia.

PURPOSE: The purpose of this study is to present a concept combining three modifications of the component separation technique (CST) in one procedure as an original solution for the management of complex subcostal abdominal wall hernia. METHODS: Between January 2010 and January 2020, seven patients presenting at the high-volume academic center with complex subcostal hernia underwent surgery in which three modifications of CST were combined into one procedure. Major complex subcostal hernia was defined by either width or length of the defect being greater than 10 cm. The following were the stages of the operative technique: (a) the "method of wide myofascial release" at the side of the hernia defect; (b) "open-book variation" of the component separation technique at the opposite side of the hernia defect; (c) a modified component separation technique for closure of midline abdominal wall hernias in the presence of enterostomies; (d) suturing of the myofascial flaps to each other to cover the defect; and (e) repair augmentation with an absorbable mesh in the onlay position. RESULTS: The median length and width of the complex subcostal hernias were 15 cm (10-19) and 15 cm (8-24), respectively. The overall morbidity rate was 57.1% (wound infection occurred in three patients, seroma in two patients, and skin necrosis in one patient). There was no hernia recurrence during the median follow-up period of 19 months. CONCLUSION: The operative technique integrating three modifications of CST in one procedure with onlay absorbable mesh reinforcement is a feasible solution for the management of complex subcostal abdominal wall hernia.

Management of epigastric, umbilical, spigelian and small incisional hernia as a day case procedure: results of long-term follow-up after open preperitoneal flat mesh technique.

PURPOSE: To investigate short and long-term outcome after the open preperitoneal flat mesh technique (OPFMT) for umbilical, epigastric, spigelian, small incisional and "port-site" hernia performed as a day case procedure. METHODS: We retrospectively analyzed records of patients who underwent OPFMT for umbilical, epigastric, Spigelian, small incisional and "port-site" hernia in ambulatory settings between 2004 and 2020 at Clinical Center of Serbia. Demographic and clinical characteristics, operative data and postoperative complications were compared between the groups. Univariate and multivariate analyses were performed to identify predictive factors for mesh infection and recurrence. RESULTS: Overall, 476 patients were divided according to the type of hernia. Early postoperative complications were similar in all study groups. Mesh infection, chronic pain and recurrence were different between groups (p = 0.013, p = 0.019 and p = 0.011, respectively). Overall recurrence rate after OPFMT was 2.5%. Hernia defect, hematoma and length of postoperative stay at the Day Surgery Unit were identified as potential predictors of mesh infection (Odds ratio 6.449, 22.143 and 1.546, respectively; p = 0.027, p = 0.011 and p = 0.038, respectively) while mesh infection was the only potential predictor of recurrence in univariate analysis. Hematoma was an independent predictor of recurrence (Odds ratio 27.068; 95% Confidence interval 2.355-311.073; p = 0.008). CONCLUSION: The OPFMT performed under local anesthesia as a day case procedure is a safe technique associated with favorable long-term outcome. Hematoma is an independent predictor of mesh infection occurrence.

Liver resection versus transarterial chemoembolization for huge hepatocellular carcinoma: a propensity score matched analysis.

To date, it is unclear which treatment modality, liver resection (LR) or transarterial chemoembolization (TACE) is the more appropriate for patients with huge (≥ 10 cm) hepatocellular carcinoma (HCC). The study aim was to compare, using propensity score matching, short- and long-term outcomes of patients with huge HCC who underwent potentially curative LR or TACE. Patients with huge HCC who had been managed at the Clinical Center by curative-intent LR or by palliative TACE between November 2001 and December 2018 were retrospectively identified. The morbidity and mortality rates and overall survival were compared between the groups before and after the propensity score matching. Independent predictors of long-term survival were determined by multivariate analysis. A total of 103 patients with huge HCC were included; 68 were assigned to the LR group and 35 to the TACE group. The overall morbidity rate was higher in the LR group than in the TACE group before matching (64.7% vs. 37.1%, p = 0.012), while there was no difference after matching (60% vs. 30%, p = 0.055). The major morbidity and 30-days mortality were similar between the groups before and after matching. The LR group was associated with longer overall survival than the TACE group before matching (p = 0.032) and after matching (p = 0.023). Total bilirubin and TACE treatment were independent prognostic factors associated with long-term survival. In patients with huge HCC, liver resection provides better long-term survival than TACE and should be considered as the initial treatment whenever possible.

A retrospective analysis of selective internal radiation therapy (SIRT) with yttrium-90 microspheres in patients with unresectable hepatic malignancies.

AIM: To evaluate the efficacy and safety of selective internal radiation therapy (SIRT). MATERIALS AND METHODS: A retrospective analysis was undertaken of all patients who underwent SIRT at a single institution. Diagnostic and therapeutic angiograms, computed tomography (CT) images, positron-emission tomography (PET) images, and planar isotope images were analysed. The response to SIRT was analysed using radiological data and tumour markers. Overall survival, complications, and side effects of SIRT were also analysed. RESULTS: The initial 12 patients were included on an intention-to-treat basis, between 21/09/2005 and 07/05/2008. All patients had advanced disease and multiple prior courses of chemotherapy. One patient did not receive yttrium-90 due to complex vascular anatomy; the remaining 11 patients underwent 13 SIRT treatment episodes following work-up angiography. A response was seen using PET in 80% of patients. Using CT, the response of the tumour to therapy in the treated hepatic segments demonstrated a 20% partial response, stable disease in 50%, and progressive disease in 30%. Estimated median survival was 229 days, with 64% of patients still alive at the time of writing. No major complications were observed, although 82% of patients experienced side-effects following SIRT, mainly nausea, vomiting, and abdominal pain. CONCLUSIONS: There have been no complications in the 12 SIRT patients. Tumour response was seen in four out of five patients who underwent PET. Objective CT response rates were mixed and are perhaps partially explained by advanced disease and limitations of using measurements to assess response. This complex and potentially hazardous service has been successfully and safely established.

AD-HOC INTERCOMPARISON OF FOUR DIFFERENT RADON EXHALATION MEASUREMENT METHODS.

It is indicated that the exposure to radon originating from the building materials is not negligible and the radon exhalation measurement should get more attention in the future. The experience with four different methods of the exhalation measurement, established in our laboratory for the purpose of the intercomparison is reported. Additionally, a comparison of advantages and disadvantages of used methods is discussed.

A prospective, randomised double-blind crossover study to examine the efficacy of strontium-89 in pain palliation in patients with advanced prostate cancer metastatic to bone.

The palliative efficacy of strontium-89 chloride has been evaluated in a prospective double-blind crossover study comparing it with stable strontium as placebo in 32 patients with prostate cancer metastatic to bone. Response was assessed 5 weeks after each treatment. 26 patients were evaluable. Complete pain relief was only reported following strontium-89 injection. Statistical comparison between placebo and strontium-89 showed clear evidence of a therapeutic response to strontium-89 compared with only a limited placebo effect (P less than 0.01).

Iodine-131-metaiodobenzylguanidine dosimetry in cancer therapy: risk versus benefit.

UNLABELLED: In the treatment of neural crest tumors, such as pheochromocytoma, with[131I]MIBG, bone marrow toxicity limits the amount of administered activity and, thus, a therapeutically useful tumor dose. METHODS: We calculated tumor doses in a series of diagnostic studies with [123I]MIBG using accurate quantification of SPECT and planar scintigraphy. By extrapolating diagnostic results to therapeutic activities of [131I]MIBG, we could compare the results with whole-body doses from a series of therapies. RESULTS: The tumor dose was DT = 2.2 mGy MBq(-1) (median value of 27 measurements, range 0.04 < or = DT < or = 20 mGy MBq(-1) and the whole-body dose in a series of 16 patients undergoing 50 therapies was DWB = 0.12 +/- 0.04 mGy MBq(-1) (mean +/- s.d.). The therapeutic ratio varied between 130 to below 10 in some patients. CONCLUSION: The results were compared with published data. We found clearly skewed distribution of tumor doses, with a majority of tumors receiving only a few mGy per MBq administered activity. In some patients, however, doses did reach 20 mGy MBq(-1).

Strontium-89 therapy: measurement of absorbed dose to skeletal metastases.

We report measurements of absorbed dose to vertebral metastases in ten patients referred for 89Sr therapy for disseminated prostatic carcinoma. Patients received a tracer dose of 85Sr at the time of 89Sr treatment and metastatic strontium retention was monitored scintigraphically for 6 mo. Metastatic 85Sr activity corrected for tissue attenuation was measured using the conjugate view principle, with special care taken to eliminate errors due to the selection of the metastatic region of interest. Metastatic volume was determined from high resolution CT images, and density inferred from Hounsfield number using the QCT bone mineral calibration of Genant and Cann. The mean absorbed dose was 850 rad/mCi (23 cGy/MBq) with a range from 220-2260 rad/mCi (6 to 61 cGy/MBq). The wide range found was consistent with the variation expected to arise due to differences in strontium renal plasma clearance (range 0.1-11.81/day) and extent of skeletal metastatic disease (varying from two small metastases to a superscan on [99mTc]MDP images) among the patients studied.

Strontium-89 therapy: strontium kinetics and dosimetry in two patients treated for metastasising osteosarcoma.

We report a study of strontium kinetics in two patients who received 89Sr therapy for disseminated osteogenic sarcoma, together with estimates of absorbed dose to the principal metastases and to bone marrow. In neither patient did tumour uptake of strontium have a significant effect on whole-body retention. In one patient, whole-body strontium kinetics agreed closely with the ICRP standard model, while in the second, retention was extremely prolonged, probably due to hypertrophic osteoarthropathy. Strontium-85 scintigraphy, surface counting and high-resolution whole-body profiles agreed in showing that in both patients tumour turnover of strontium was very rapid, with a biological half-life of only a few days. Absorbed dose to tumour was found to be comparable in magnitude to the mean bone-marrow dose. We have no reason to believe that 89Sr therapy was of clinical benefit to either patient.

Strontium-89 chloride for pain palliation in prostatic skeletal malignancy.

In a multi-centre study strontium-89 was shown to be effective in relieving bone pain from prostatic carcinoma in patients who had failed conventional therapies. Of 83 patients assessed at 3 months, following the administration of a dose of at least 1.5 MBq/kg, 75% derived benefit and 22% became pain free. Symptomatic improvement usually occurred within 6 weeks and continued for between 4 and 15 months (mean 6 months). Based on the dose estimation part of this study the recommended dose of strontium-89 is 150 MBq. Toxicity was low, provided platelet levels were above 100 x 10(9) l-1 at the time of treatment. Repeat treatments with strontium-89 may be given at intervals of not less than 3 months. Strontium-89 is administered intravenously on an out-patient basis with no special radiological protection precautions.

Strontium-89 radionuclide therapy: a dosimetric study using impulse response function analysis.

In a series of patients receiving 89Sr palliation for metastasised prostatic carcinoma, strontium renal plasma clearance was found to vary from 0.14 to 11.81 day-1, and the extent of skeletal metastatic disease seen on 99Tcm-MDP images varied from a few small metastases to a superscan. Using a numerical technique based on impulse response function (IRF) analysis, we have investigated the effect of such variation between patients on 89Sr dosimetry. The whole-body IRF, HWB(t), is defined by the deconvolution of the whole-body strontium retention function, RWB(t), with the plasma retention function, P(t). For patients with minimal metastatic bone disease we assumed HWB(t) = HO(t), where HO is the IRF derived from the International Commission on Radiological Protection model for normal strontium metabolism. The strontium plasma clearance, k, was allowed to vary, and the resulting variation of RWB(t), P(t) and absorbed dose to bone marrow calculated. By convoluting P(t,k) with the IRF measured for a discrete metastasis, the effect of varying k on tumour dose was investigated. Tumour and bone marrow dose were shown to change by a factor of three as k varied over the range observed in patients. For patients with extensive metastatic bone disease we assumed HWB(t) = (1-beta)HO(t) + beta HS(t), where HS was the IRF measured for a superscan patient and beta was a parameter reflecting the extent of skeletal metastatic disease. The effect of varying beta on tumour and bone marrow dose was investigated, and dose shown to decrease by a factor of five as beta increased from zero to unity. Impulse response function analysis was found to be a powerful and useful aid in clarifying the relationship between strontium kinetics and 89Sr dosimetry.

The limitations of the dual radionuclide subtraction technique for the external detection of tumours by radioiodine-labelled antibodies.

A dual radionuclide subtraction technique for external detection of tumours has been evaluated to determine the viability of the method for use with radioisotope labelled antibodies. A number of external scintigraphic investigations have been carried out with 131I-labelled antibodies to carcinoembryonic antigen (CEA). The investigations were performed on patients with metastatic disease known to produce CEA. The dual radionuclide subtraction technique was used to account for the blood and tissue background. The 131I-labelled antibodies were found to localise in the metastatic lesions, but the subtraction technique using 99Tcm-labelled HSA and pertechnetate gave ambiguous results, which included the production of artefacts. The ambiguities noted in the clinical results were substantiated by experimental data, which highlight the unreliability of this technique.

Palliation of bone metastases in prostate cancer. Hemibody irradiation or strontium-89?

The palliation of bone pain is a common clinical problem once metastatic prostate cancer has escaped from hormonal control. This retrospective study compares the results of treatment using hemibody irradiation (HBI) at the Royal Marsden Hospital (27 cases) with isotope therapy using the bone-seeking isotope strontium-89 (89Sr) at Southampton General Hospital (51 cases). Prior to analysis patients were matched for potential prognostic factors (performance status, bone scan extent of disease, age, histology and duration of hormone response) to minimize the effect of treatment selection bias. Pain control assessed at 3 months was similar for HBI and matched 89Sr cases, with 63% and 52% respectively showing some benefit. Median survival was similar for these groups at 20 and 21 weeks respectively. The unmatched 89Sr group, which had more favourable prognostic factors, had a better outcome with 96% showing improvement in pain and with a median survival of 59 weeks. Subsequent univariate analysis demonstrated that performance status and extent of disease on bone scan were of overriding importance in determining outcome. Transfusion requirements were higher for the HBI group than for the matched 89Sr group (50% and 25% respectively) but other bone marrow toxicity was similar. Despite routine anti-emetic therapy 37% of patients treated with HBI had some nausea or vomiting. Although expensive, 89Sr appears as effective a treatment option as HBI. Response is most likely with either approach when patients have a good performance status and a limited extent of disease.

The relationship of 67Ga uptake to citrate dose, compared with 67Ga-chloride and 67Ga-transferrin in rodent tissues and tumours.

The uptake of 67Ga-citrate in the tissues of the mouse and rat and in two mouse tumours, S180 and PC6, has been measured and shown to be independent of the citrate concentration of the injection dose. The tumour uptake and tissue distribution of 67Ga-chloride and 67Ga-transferrin were identical with those of the citrate complex. Whole-body retention data for 67Ga-citrate in the mouse for 14 days after injection are also presented.

Strontium kinetics in metastasized prostatic carcinoma: a comparison with the predictions of impulse response function analysis.

Amongst patients referred for 89Sr palliation of disseminated prostatic carcinoma, we have found wide variations in extent of skeletal metastatic disease and in strontium renal plasma clearance. A numerical technique using impulse response function analysis is reviewed which enables the effect of such variations on the total body, plasma and metastatic strontium retention functions to be calculated. The prediction of the model are compared with kinetic data from patients presenting for radiostrontium therapy, and correlations that have important implications for 89Sr dosimetric studies are confirmed. The simplest kinetic data required to allow for these effects in studies of dose-response and haematological toxicity following radio-strontium treatment are discussed and attention is drawn to a small group of patients who may form a significant exception to the general model.

Comparison of two methods for high purity germanium detector efficiency calibration for charcoal canister radon measurement.

The charcoal canister method of radon measurement according to US Environment Protection Agency protocol 520/5-87-005 is widely used for screening. This method is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. For the purpose of gamma spectrometry, appropriate efficiency calibration of the measuring system must be performed. The most usual method of calibration is using standard canister, a sealed canister with the same matrix and geometry as the canisters used for measurements, but with the known activity of radon. In the absence of standard canister, a different method of efficiency calibration has to be implemented. This study presents the results of efficiency calibration using the EFFTRAN efficiency transfer software. Efficiency was calculated using a soil matrix cylindrical secondary reference material as a starting point. Calculated efficiency is then compared with the one obtained using standard canister and applied to a realistic measurement in order to evaluate the results of the efficiency transfer.

Uncertainty evaluation in radon concentration measurement using charcoal canister.

Active charcoal detectors are used for testing the concentration of radon in dwellings. The method of measurement is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. The contributions to the final measurement uncertainty are identified, based on the equation for radon activity concentration calculation. Different methods for setting the region of interest for gamma spectrometry of canisters were discussed and evaluated. The obtained radon activity concentration and uncertainties do not depend on peak area determination method.