Utility of routine oral contrast study for detecting postesophagectomy anastomotic leak - a systematic review and meta-analysis.

Oral contrast studies are used to detect anastomotic leak (AL) postesophagectomy. However, recent evidence suggests oral contrast studies have low sensitivity in detecting ALs, and their false positive results can lead to unnecessary prolonged hospital stay. The objective of this study was to determine if oral contrast studies should be used routinely post-esophagectomy for cancer. A systematic literature search was conducted for studies published between January 1990 and June 2018. Data extracted for analyses included type of esophagectomy, operative morbidity (such as AL and pneumonia), mortality rates, timing of contrast study, and type of oral contrast used. The sensitivity, specificity, and positive and negative predictive values of routine oral contrast studies to detect AL were calculated using the aforementioned variables. Two hundred and forty-seven studies were reviewed with 16 studies included in the meta-analysis. Postoperative oral contrast study was performed in 94.0% of cases between day 5 and 7. The rates of early and delayed leaks were 2.4% (1.8%-3.3%) and 2.8% (1.8%-4.4%), respectively. Routine contrast studies have a sensitivity and specificity of 0.44 (0.32-0.57) and 0.98 (0.95-0.99), respectively. Analysis of covariates revealed that sensitivity is reduced in centers with a higher volume of cases (greater than 15 per year: 0.50 [0.34-0.75; p = 0.0008]) and specificity was higher in centers with a lower leak rate. Given its poor sensitivity and inability to detect early/delayed AL, oral contrast study should be used selectively with endoscopy and/or computerized tomography scan to assess surgical anastomoses following esophagectomy.

Plerixafor plus pegfilgrastim is a safe, effective mobilization regimen for poor or adequate mobilizers of hematopoietic stem and progenitor cells: a phase I clinical trial.

The safety, kinetics and efficacy of plerixafor+pegfilgrastim for hematopoietic stem and progenitor cell (HSPC) mobilization are poorly understood. We treated 12 study patients (SP; lymphoma n=10 or myeloma n=2) with pegfilgrastim (6 mg SC stat D1) and plerixafor (0.24 mg/kg SC nocte from D3). Six SP were 'predicted poor-mobilizers' and six were 'predicted adequate-mobilizers'. Peripheral blood (PB) CD34(+) monitoring commenced on D3. Apheresis commenced on D4. Comparison was with 22 historical controls (HC; lymphoma n=18, myeloma n=4; poor mobilizers n=4), mobilized with pegfilgrastim alone. Eight (67%) SP had PB CD34(+) count ⩽5 × 10(6)/L D3 post pegfilgrastim; all SP surpassed this threshold the morning after plerixafor. In SP, PBCD34(+) counts peaked D4 6/12 (50%), remaining ⩾5 × 10(6)/L for 4 days in 8/12 (67%). All SP successfully yielded target cell numbers (⩾2 × 10(6)/kg) within four aphereses. After maximum four aphereses, median total CD34+ yield was higher in SP than HC; 8.0 (range 2.4-12.9) vs 4.8 (0.4-14.0) × 10(6)/kg (P=0.04). Seven of twelve (58%) SP achieved target yield after one apheresis. Flow cytometry revealed no tumor cells in PB or apheresis product of SP. Plerixafor+pegfilgrastim was well tolerated with bone pain (n=2), diarrhoea (n=2) and facial paraesthesiae (n=3). Plerixafor+pegfilgrastim is a simple, safe and effective HSPC mobilization regimen in myeloma and lymphoma, in both poor and good mobilizers, and is superior to pegfilgrastim alone.

Perioperative epidural analgesia reduces cancer recurrence after gastro-oesophageal surgery.

BACKGROUND: Recent interest has focused on the role of perioperative epidural analgesia in improving cancer outcomes. The heterogeneity of studies (tumour type, stage and outcome endpoints) has produced inconsistent results. Clinical practice also highlights the variability in epidural effectiveness. We considered the novel hypothesis that effective epidural analgesia improves cancer outcomes following gastro-oesophageal cancer surgery in patients with grouped pathological staging. METHODS: Following institutional approval, a database analysis identified 140 patients, with 2-year minimum follow-up after gastro-oesophageal cancer surgery. All patients were operated on by a single surgeon (2005-2010). Information pertaining to cancer and survival outcomes was extracted. RESULTS: Univariate analysis demonstrated a 1-year 14% vs. 33% (P = 0.01) and 2-year 27% vs. 40% [hazard ratio (HR)=0.59; 95% CI, 0.32-1.09, P = 0.087] incidence of cancer recurrence in patients with (vs. without) effective (> 36 h duration) epidural analgesia, respectively. Multivariate analysis demonstrated increased time to cancer recurrence (HR = 0.33; 95% CI: 0.17-0.63, P < 0.0001) and overall survival benefit (HR = 0.42; 95% CI: 0.21-0.83, P < 0.0001) at 2-year follow-up following effective epidural analgesia. Subgroup analysis identified epidural-related cancer recurrence benefit in patients with oesophageal cancer (HR = 0.34; 95% CI: 0.16-0.75, P = 0.005) and in patients with tumour lymphovascular space infiltration (LVSI), (HR = 0.49; 95% CI: 0.26-0.94, P = 0.03). Effective epidural analgesia improved estimated median time to death (2.9 vs. 1.8 years, P = 0.029) in patients with tumour LVSI. CONCLUSIONS: This study found an association between effective post-operative epidural analgesia and medium-term benefit on cancer recurrence and survival following oesophageal surgery. A prospective study that controls for disease type, stage and epidural effectiveness is warranted.

Pegfilgrastim compared with filgrastim for cytokine-alone mobilization of autologous haematopoietic stem and progenitor cells.

Haematopoietic stem and progenitor cells (HSPC) mobilization, using cytokine-alone, is a well-tolerated regimen with predictable mobilization kinetics. Single-dose pegfilgrastim mobilizes HSPC efficiently; however, there is surprisingly little comparative data on its use without chemotherapy for HSPC mobilization. Pegfilgrastim-alone and filgrastim-alone mobilization regimens were compared in 52 patients with haematological malignancy. Pegfilgrastim 12 mg (n=20) or 6 mg (n=2) was administered Day 1 (D1) in 22 patients (lymphoma n=17; myeloma n=5). Thirty historical controls (lymphoma n=18; myeloma n=12) received filgrastim 10 mcg/kg daily from D1. Peripheral blood (PB) CD34(+) counts reached threshold (5 × 10(6)/L) and apheresis commenced on D4(4-5) and D4(4-6). Median PB CD34(+) cell count on D1 of apheresis was similar (26.0 × 10(6)/L (2.5-125.0 × 10(6)/L) and 16.2 × 10(6)/L (2.6-50.7 × 10(6)/L); P=0.06), for pegfilgrastim and filgrastim groups, respectively. Target yield (2 × 10(6) per kg CD34(+) cells) was collected in 20/22 (91%) pegfilgrastim patients and 24/30 (80%) in the filgrastim group (P=0.44), in a similar median number of aphereses (3(1-4) versus 3(2-6), respectively; P=0.85). A higher proportion of pegfilgrastim patients tended to yield 4 × 10(6) per kg CD34(+) cells; 16/22 (73%) versus 14/30 (47%) filgrastim patients (P=0.09). One pegfilgrastim patient developed hyperleukocytosis that resolved without incident. Pegfilgrastim-alone is a simple, well-tolerated, and attractive option for outpatient-based HSPC mobilization with similar mobilization kinetics and efficacy to regular filgrastim.

FDG-PET metabolic response predicts outcomes in anal cancer managed with chemoradiotherapy.

BACKGROUND: The aim was to investigate the correlation between (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic response to chemoradiotherapy and clinical outcomes in squamous cell carcinoma (SCC) of the anus. METHODS: A total of 48 patients with biopsy-proven anal SCC underwent FDG-PET scans at baseline and post chemoradiotherapy (54 Gy, concurrent 5-FU/mitomycin). Kaplan-Meier analysis was used to determine survival outcomes according to FDG-PET metabolic response. RESULTS: In all, 79% patients (n=38) had a complete metabolic response (CMR) at all sites of disease, 15% (n=7) had a CMR in regional nodes but only partial response in the primary tumour (overall partial metabolic response (PMR)) and 6% (n=3) had progressive distant disease despite CMR locoregionally (overall no response (NR)). The 2-year progression-free survival (PFS) was 95% for patients with a CMR, 71% for PMR and 0% for NR (P<0.0001). The 5-year overall survival (OS) was 88% in CMR, 69% in PMR and 0% in NR (P<0.0001). Cox proportional hazards regression analyses for PFS and OS found significant associations for incomplete (PMR+NR) vs complete FDG-PET response to treatment only, (HR 4.1 (95% CI: 1.5-11.5, P=0.013) and 6.7 (95% CI: 2.1-21.6, P=0.002), respectively). CONCLUSION: FDG-PET metabolic response to chemoradiotherapy in anal cancer is significantly associated with PFS and OS, and in this cohort incomplete FDG-PET response was a stronger predictor than T or N stage.

Metabolic response of rectal cancer assessed by 18-FDG PET following chemoradiotherapy is prognostic for patient outcome.

BACKGROUND: Complete pathological response has proven prognostic benefits in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy. Sequential 18-FDG PET may be an early surrogate for pathological response to chemoradiotherapy. OBJECTIVES: The aim of this study was to identify whether metabolic response measured by FDG PET following chemoradiotherapy is prognostic for tumor recurrence and survival following neoadjuvant therapy and surgical treatment for primary rectal cancer. METHODS: Patients with primary rectal cancer treated by long-course neoadjuvant chemoradiotherapy followed by surgery had FDG PET performed before and 4 weeks after treatment, before surgical resection was performed. Retrospective chart review was undertaken for patient demographics, tumor staging, recurrence rates, and survival. RESULTS: : Between 2000 and 2007, 78 patients were identified (53 male, 25 female; median age, 64 y). After chemoradiotherapy, 37 patients (47%) had a complete metabolic response, 26 (33%) had a partial metabolic response, and 14 (18%) had no metabolic response as assessed by FDG PET (1 patient had missing data). However, only 4 patients (5%) had a complete pathological response. The median postoperative follow-up period was 3.1 years during which 14 patients (19%) had a recurrence: 2 local, 9 distant, and 3 with both local and distant. The estimated percentage without recurrence was 77% at 5 years (95% CI 66%-89%). There was an inverse relationship between FDG PET metabolic response and the incidence of recurrence within 3 years (P = .04). Kaplan-Meier analysis of FDG PET metabolic response and overall survival demonstrated a significant difference in survival among patients in the 3 arms: complete, partial, and no metabolic response (P = .04); the patients with complete metabolic response had the best prognosis. CONCLUSION: Complete or partial metabolic response on PET following neoadjuvant chemoradiotherapy and surgery predicts a lower local recurrence rate and improved survival compared with patients with no metabolic response. Metabolic response may be used to stratify prognosis in patients with rectal cancer.

SLCO1B1 variants and statin-induced myopathy--a genomewide study.

BACKGROUND: Lowering low-density lipoprotein cholesterol with statin therapy results in substantial reductions in cardiovascular events, and larger reductions in cholesterol may produce larger benefits. In rare cases, myopathy occurs in association with statin therapy, especially when the statins are administered at higher doses and with certain other medications. METHODS: We carried out a genomewide association study using approximately 300,000 markers (and additional fine-mapping) in 85 subjects with definite or incipient myopathy and 90 controls, all of whom were taking 80 mg of simvastatin daily as part of a trial involving 12,000 participants. Replication was tested in a trial of 40 mg of simvastatin daily involving 20,000 participants. RESULTS: The genomewide scan yielded a single strong association of myopathy with the rs4363657 single-nucleotide polymorphism (SNP) located within SLCO1B1 on chromosome 12 (P=4x10(-9)). SLCO1B1 encodes the organic anion-transporting polypeptide OATP1B1, which has been shown to regulate the hepatic uptake of statins. The noncoding rs4363657 SNP was in nearly complete linkage disequilibrium with the nonsynonymous rs4149056 SNP (r(2)=0.97), which has been linked to statin metabolism. The prevalence of the rs4149056 C allele in the population was 15%. The odds ratio for myopathy was 4.5 (95% confidence interval [CI], 2.6 to 7.7) per copy of the C allele, and 16.9 (95% CI, 4.7 to 61.1) in CC as compared with TT homozygotes. More than 60% of these myopathy cases could be attributed to the C variant. The association of rs4149056 with myopathy was replicated in the trial of 40 mg of simvastatin daily, which also showed an association between rs4149056 and the cholesterol-lowering effects of simvastatin. No SNPs in any other region were clearly associated with myopathy. CONCLUSIONS: We have identified common variants in SLCO1B1 that are strongly associated with an increased risk of statin-induced myopathy. Genotyping these variants may help to achieve the benefits of statin therapy more safely and effectively. (Current Controlled Trials number, ISRCTN74348595.)

Screening of multiparous women to avoid transfusion-related acute lung injury: a single centre experience.

The aim of this study was to investigate which approach for serological testing of multiparous donors might be feasible and effective to reduce the risk of transfusion-related acute lung injury (TRALI). TRALI is a serious adverse event of blood transfusion. Antibodies to granulocytes and human leucocyte antigens (HLAs) are frequently detected in sera of implicated donors. These donors are often multiparous women. A general deferral of female plasma or screening strategies for leucocyte antibodies has been proposed to increase blood safety. A prospective study was initiated in 2003. Until 2006, serum samples from all female donors reporting three or more pregnancies (n = 229) were screened for the presence of antibodies against granulocytes and HLAs by immunofluorescence and agglutination tests as well as by a commercial HLA enzyme immunoassay. In total, 40% of all multiparous women were reactive in one of the assays. Twenty-nine percent of the reactive sera contained antibodies to granulocytes but not to HLAs. During the observation period, three TRALI reactions occurred in our hospital, two of which would have been prevented if the screening program had been extended to all previously pregnant donors. We conclude from these data that, not unexpectedly, the number of previous pregnancies is not a reliable indicator for the likelihood of inducing TRALI. More importantly, screening strategies for antibodies that might induce TRALI should probably not be reduced to HLA antibody screening. This finding awaits further research.

Current eczema in children is related to Der f 1 exposure but not to Der p 1 exposure.

BACKGROUND: Mite allergen exposure is an important risk factor for specific IgE production and is associated with asthma, hay fever and eczema. Whether these associations are independent of mite species has not been investigated so far. OBJECTIVES: To investigate the influence of exposure to the major house dust mite (HDM) allergens Der p 1 and Der f 1 on sensitization, respiratory symptoms, and especially on eczema and related skin symptoms in 6-7-year-old children. METHODS: In a cross-sectional study in Augsburg (Bavaria, Germany) 1669 school beginners (mean age 6.5 years) were investigated in 1996. The concentrations of Der p 1 and Der f 1 were measured in dust samples from mattresses of 1081 children by enzyme-linked immunosorbent assay. The prevalence of atopy-related health outcomes was assessed by questionnaire, dermatological examination, skin prick testing and determination of specific serum IgE concentrations by radioallergosorbent test. Information about covariates was taken from questionnaires and interview data. Logistic regression was used to adjust for confounding. RESULTS: The mean concentrations of Der p 1 and Der f 1 were 0.68 and 0.79 microg g(-1) dust, respectively. The relationship between the two species-specific allergens in individual homes was poor (Pearson correlation 0.2). Influencing variables were bedroom-sharing (Der p 1) and social status of the parents (Der f 1). Respiratory diseases were positively associated with both allergen concentrations [odds ratio (OR) between 1.1 and 2.6]. These associations were significant for sneezing attacks (Der p 1 and Der f 1). Reported prevalence of current (in the last 12 months) itchy skin rash was significantly associated with exposure to Der f 1 only (OR 2.4, P < 0.003); also a diagnosis of atopic eczema on the day of investigation was positively associated with Der f 1 only (OR 1.8, P = 0.14). CONCLUSIONS: Studies on the effects of HDM exposure on eczema and allergies should consider specific effects of different mite species. This might have implications on assessment of allergen exposure and consecutive prevention or therapeutic measures.

The effect of environmental tobacco smoke on eczema and allergic sensitization in children.

BACKGROUND: The negative impact of environmental tobacco smoke (ETS) on airway diseases in children is well known. Whether there is an effect on atopic eczema is not clear. OBJECTIVES: To determine the impact of ETS on atopic eczema, allergic sensitization and allergic airway diseases in 1669 school beginners. METHODS: The prevalence of atopy-related health outcomes was assessed by questionnaire, dermatological examination, skin prick testing and specific immunoglobulin E measurement. Exposure assessments were based on measurement of cotinine [expressed as cotinine to creatine ratio (CCR)] in spot urine samples (n = 1220) together with questionnaire and interview data on smoking behaviour of the parents. RESULTS: In the total study group, prevalence of atopic eczema diagnosed on examination was significantly associated with urinary CCR values. The odds ratio (OR) and 95% confidence interval (CI), calculated for an increase of 100 ng mg-1 CCR was 1.97 (95% CI 1.23-3.16). The prevalence of skin manifestations according to questionnaire data as well as a history of asthma, wheezing, and hay fever were positively although not significantly associated with ETS exposure. When genetically predisposed children (defined by the presence of parental atopy) were compared with children whose parents had no atopy, the ORs of allergic outcome variables were generally higher in the first group. In the group of predisposed children, significant associations with urinary CCR were found for allergic sensitization against house dust mites as measured by skin prick test (OR 3.10, 95% CI 1.63-5.90). CONCLUSIONS: Children are at a higher risk of developing an atopic eczema when exposed to ETS and genetically predisposed children are at higher risk of developing a sensitization against house dust mites.

[Studying school beginners in western and eastern Germany: allergy trends and sensitisations 1991-2000]. / Die Schulanfängerstudie in West- und Ostdeutschland (SAWO): Trends von Allergien und Sensibilisierungen 1991-2000.

AIM: Aim of the study is to examine the hypotheses of a steeper increase in allergies and allergic sensitisations in East than in West German children between 1991 and 2000. METHOD: Between 1991 and 2000 we yearly repeated cross-sectional studies (SAWO: Study on school beginners) and asked 36,645 parents about diagnoses and symptoms of allergies in their six-year old children (response: 79 %). The study was done in Leipzig, Halle, Merseburg, Magdeburg, small towns in the Altmark region, Duisburg, Essen, Köln and Borken during spring. An allergological investigation was included 1991, 1994, 1997 and 2000. Dermatologists diagnosed a prevalent atopic eczema, administered a skin prick test (n = 7,229) and blood was taken for the determination of specific IgE antibodies against common allergens (n = 7,714, RAST). Odds Ratios (OR) for trend were calculated separately for the data from East and West Germany and are given along with their 95% confidence intervals. RESULTS: Allergies and their symptoms (exception: atopic eczema) were less prevalent in East German children born before the reunification than in West German ones. In East as well as in West Germany bronchial asthma was diagnosed more often in 2000 than in 1991 (OR East: 2.42 [1.78-3.28] West: 2.07 [1.43-3.00]). In contrast the prevalence of atopic eczemas was more than halved between 1991 and 2000. Of all symptoms and diagnoses of allergies only hay fever and its symptoms showed an upward trend in East Germany which was steeper than the trend in West Germany (OR East: 4.41 [3.17-6.13] West: 1.74 [1.19-2.57]). This can partly be explained by a parallel trend in sensitisation against grass pollen. CONCLUSION: The spatial and temporal pattern of the allergic diseases bronchial asthma, hay fever and atopic eczema in six-year old children from Germany is different. The expected steeper increase of allergies in East than in West Germany could only be shown for hay fever.

Targeting melanoma with 211At/131I-methylene blue: preclinical and clinical experience.

The increasing incidence of melanoma and a lack of effective therapy have stimulated a search for new methods of early detection and treatment of the disease. Melanin synthesized in melanoma cells presents a unique target to which the treatment can be selectively addressed, provided the pigment is recognized by a suitable drug. Methylene blue possesses a high affinity for melanin and, therefore, accumulates preferentially in melanoma cells. Since not directly toxic to the tumor, methylene blue serves as a carrier for radioisotopes and, once taken up by melanoma cells, acts as a selectively localized source of radiation. Hence, radioderivatives of the compound can be used for diagnosis and therapy of disseminated melanoma. 131I-methylene blue in conjunction with gamma camera imaging has already proved in clinical studies to be a useful tool for the detection of early melanoma dissemination. 211At-methylene blue exceptional efficacy in treating melanoma and preventing its metastatic spread without damaging normal structures when administered systemically to human melanoma-bearing mice led to the approval of this alpha-particle emitting methylene blue derivative for the Phase I clinical trial.

Regulation of the insulin-like developmental pathway of Caenorhabditis elegans by a homolog of the PTEN tumor suppressor gene.

The human PTEN tumor suppressor gene is mutated in a wide variety of sporadic tumors. To determine the function of PTEN in vivo we have studied a PTEN homolog in Caenorhabditis elegans. We have generated a strong loss-of-function allele of the PTEN homolog and shown that the deficient strain is unable to enter dauer diapause. An insulin-like phosphatidylinositol 3-OH kinase (PI3'K) signaling pathway regulates dauer-stage entry. Mutations in either the daf-2 insulin receptor-like (IRL) gene or the age-1 encoded PI3'K catalytic subunit homolog cause constitutive dauer formation and also affect the life span, brood size, and metabolism of nondauer animals. Strikingly, loss-of-function mutations in the age-1 PI3'K and daf-2 IRL genes are suppressed by loss-of-function mutations in the PTEN homolog. We establish that the PTEN homolog is encoded by daf-18, a previously uncloned gene that has been shown to interact genetically with the DAF-2 IRL AGE-1 PI3'K signaling pathway. This interaction provides clear genetic evidence that PTEN acts to antagonize PI3'K function in vivo. Given the conservation of the PI3'K signaling pathway between C. elegans and mammals, the analysis of daf-18 PTEN mutant nematodes should shed light on the role of human PTEN in the etiology of metabolic disease, aging, and cancer.

Low-doses of ionising radiation induce melanoma metastases and trigger the immune system--adrenal axis feedback loop.

Low-doses of ionising radiation are frequently implicated in triggering and/or accelerating the growth of skin and other malignancies. It seemed probable that the radiation at similar dose levels might initiate metastasis from already existing tumours. Highly pigmented human melanoma xenograft that had lost its ability for a spontaneous metastasising and grown subcutaneously in athymic mice was exposed to very low and well-defined doses of ionising radiation to determine whether low linear energy transfer radiation can restore metastatic potential of the tumour. To ensure that all effects derived from radiation-activated neoplastic cells only, I was delivered selectively to the cutaneous melanoma instead of using the external beam. The direct response of these tumours to radiation was monitored by determining the growth rate of the lesions. Histopathological methods were employed to detect metastases. The lowest radiation dose of approximately 6 cGy deposited in the tumours initiated metastatic spread in all animals. Gradual increase of the radiation doses diminished both the frequency of the appearance of metastases and their distance from the primary lesions. There were no metastases from non-irradiated melanomas. The highest dose used (60 cGy) did not affect significantly the growth of cutaneous (primary) tumours, but lower doses that enhanced inflammatory infiltration of the lesions reduced tumour growth. Such radiation-stimulated immune responses were accompanied by increased pigmentation in cutaneous lesions and activation of the adrenal cortex indicating that the immune system-adrenal axis feedback loop had been triggered. The results demonstrate that very low-doses of ionising radiation induce melanoma metastases. The phenomenon is accompanied by the stimulation of the immune system-adrenal axis feedback loop that regulates eicosanoid synthesis, thereby suggesting an involvement of these molecules in the process. Radiation doses approaching the therapeutic level do not initiate melanoma dissemination.

Early detection of melanoma metastases with radioiodinated methylene blue.

Melanin synthesised in melanoma cells presents a unique target to which the treatment can be selectively addressed, provided the pigment is recognised by a suitable drug. Methylene blue (MTB) possesses a high affinity for melanin and, therefore, accumulates preferentially in melanoma cells. Since not directly toxic to the tumour, MTB serves as a carrier for radioisotopes and, once taken up by melanoma cells, acts as a selectively localised source of radiation. Hence, radioderivatives of the compound can be used for both diagnosis and therapy of disseminated melanoma. Eleven patients with confirmed metastatic melanoma and one with a recent local recurrence were studied using radioiodinated (iodine-123 or iodine-131) MTB and a gamma camera. Biopsies of cutaneous lesions were taken to determine directly the compound uptake in tumours. This first clinical investigation concerning the diagnostic potential of radioiodinated MTB in patients with disseminated melanoma confirmed the existence of approximately 80% of internal lesions previously identified by routine methods and, additionally, enabled detection of unknown secondaries in 6 of 12 patients studied. There were no false-positive gamma camera images regardless of whether 123I or 131I was used. 131I proved to be more suitable than 123I for detecting melanoma metastases with radioiodinated MTB. Hazy images of the lesions treated with external beam radiation and/or some drugs suggest that initial radio- and chemotherapy might affect MTB uptake in melanoma metastases and reduce the clarity of the scintigrams obtained from a gamma camera. However, small, untreated internal lesions that cannot be visualised easily with the standard diagnostic methods are revealed with 131I-MTB regardless of their localisation. It is concluded that use of radioiodinated MTB in conjunction with gamma camera or positron emission tomographic imaging might prove to be a useful and accessible tool for the detection of early melanoma dissemination.

De novo acquisition of neuronal polarity in retinoic acid-induced embryonal carcinoma cells.

The mouse embryonal carcinoma cell line PCC7-Mz1 represents an advantageous model to study acquisition of polarity by neurons. During the first two days after differentiation is induced by the addition of retinoic acid, the neuronal derivatives develop extensions which for at least four more days do not differ from each other in growth characteristics, morphology, and marker expression. Beginning around differentiation day 6 and following the relocation of the nucleus from a central to a polar position in the cell soma, the morphology and marker expression changes dramatically: expression of MAP2 diminishes and eventually disappears in the thinner neurite (future axon), which originates at the nucleated pole, but remains strong in the branched, broad based neurite(s). The opposite changes in expression are observed for synaptophysin, together with a clustering of the vesicle protein in varicosity-like areas. Complete segregation of expression of the two markers is achieved around day 12, shortly followed by dendrite-specific location of MAP2 mRNA and the ability to generate and conduct action potentials. Our studies add several aspects to the process of neuronal polarity acquisition, as it was previously studied in primary cultures of embryonic neurons: (i) we monitored neuronal differentiation from the birth of neurons, rather than from later and less defined maturation stages, (ii) cell nucleus relocation may be associated with the induction of neuronal polarity, and (iii) functional competence of neurons is closely associated with previous acquisition of polarity. Acquisition of polarity by PCC7-Mz1 neuronal derivatives probably refers to de novo acquisition rather than to reestablishment of polarity.

Radioiodinated methylene blue for melanoma targeting: chemical characterisation and tumour selectivity of labelled components.

Radioiodinated methylene blue contains a mixture of components showing selective uptake in human pigmented melanoma, and it has potential for imaging and therapy. Nuclear magnetic resonance and mass spectroscopic studies show that the majority of the radioactivity (85%) is in the form of monoiodinated methylene blue, 4-iodo-3-methylamino-7-dimethylaminophenaza thionium chloride. The amino group ortho-to iodine has become demethylated to a mono-methylamino group. The remainder (15%) of the mixture is the doubly labelled 4,5-diiodo-3,7-bis(methylamino) phenazathionium chloride. The separated components show similar tumour selectivity in athymic mice bearing human pigmented melanomas.

211At-methylene blue for targeted radiotherapy of disseminated melanoma: microscopic analysis of tumour versus normal tissue damage.

The present stage of our preclinical investigations of targeted radiotherapy for melanoma with 3,7-(dimethylamino)phenazathionium chloride [methylene blue (MTB)] labelled with astatine-211 (211At), an alpha-particle emitter, concerns toxicity of the treatment, as well as macro- and microscopic evaluation of its efficacy. Fragments of two human melanoma xenografts, pigmented HX118 and non-pigmented HX34 (used as a control), were implanted s.c. into nude mice subsequently treated with two doses of 211At-MTB injected i.v. Alterations in tumour growth rate were related to microscopic damage caused by 211At-MTB to the lesions, as determined by light microscopy using histopathological techniques. 211At-MTB-dependent growth inhibition of pigmented melanoma occurred either instantly or as a gradual reduction in the tumour growth rate. At a later stage, lesions that ceased to grow immediately consisted of quiescent, heavily pigmented tumour cells, as well as advanced fibrosis, and were extensively infiltrated by melanin-laden phagocytes. Large, unresorbed and often calcified necrotic deposits characterised the tumours responding gradually to the treatment. 211At-MTB remained non-toxic in normal organs. Only a relative number of small lymphocytes in the groin lymph nodes in a minority of animals was temporarily reduced, most often in conjunction with the treatment of pigmented tumours. The data demonstrated a high therapeutic effectiveness of 211At-MTB towards pigmented melanoma at the expense of negligible injury to normal tissues, and revealed that the macroscopic determination of tumour growth rate often underestimated an efficacy of the applied treatment.

[211At]methylene blue for targeted radiotherapy of human melanoma xenografts: dose fractionation in the treatment of cutaneous tumours.

3,7-(dimethylamino) phenazathionium chloride [methylene blue (MTB)] labelled with alpha-particle emitter astatine-211 (211At) selectively accumulates in melanoma cells due to an exceptionally high affinity of MTB to melanin, and proves to be a very effective agent in targeting radiotherapy for pigmented human melanoma grown in mice. This study aimed at a selection of the most advantageous [211At]MTB dose fractionation leading to irreversible regression of the treated lesions. Nude mice bearing subcutaneous human melanoma xenografts of either highly pigmented HX118 or poorly pigmented HX34 human melanoma were treated with [211At]MTB administered intravenously. The treatment was performed using three different schedules of [211At]MTB fractionation: a single large dose, five fractions delivered sequentially every 48 h and two to five fractions given with a mean frequency of one per week. The effectiveness of [211At]MTB treatment was assessed by determination of the growth rate of cutaneous tumours and length of time between tumour implantation and killing of moribund mice. [211At]MTB applied with a mean frequency of one fraction per week appeared to be the most efficient treatment for highly pigmented HX118 melanomas. Its effectiveness was dependent on [211At]MTB activity used per fraction and the size of the cutaneous tumours at the beginning of the treatment. A total dose of [211At]MTB seemed of less importance. An irreversible regression of the lesions was achieved. Poorly pigmented cutaneous melanoma xenografts were affected most significantly by [211At]MTB applied as five fractions given every 48 h. The treatment caused a temporary inhibition of tumour growth after which the lesions regained the control growth rate. These and previous results suggest that [211At]MTB could successfully control the growth of already formed lesions of pigmented melanoma, as well as prevent metastatic spread of the tumour, provided an appropriate fractionation régime of the radiolabelled compound is employed.