A comparative review of potential ammonia-based carbon capture systems.

Carbon capturing technologies are recognized as a cornerstone solution in reducing greenhouse gas emissions to meet the 2050 emissions targets set during the past Paris agreement. Recently, ammonia has become a major carbon-free chemical to absorb CO2 emissions from flue gases. In this regard, this paper concerns the recently developed novel ammonia-based carbon capturing systems in the open literature and comparatively evaluates them from various perspectives in addition to discussing their advantages and disadvantages. The systems considered are basically classified into three categories, namely renewable energy-based systems, energy savings-focused systems, and Integrated Gasification Combined Cycle (IGCC)-based systems. Then, comparative assessments of the novel systems are conducted to see their advantages and weaknesses as compared to the typical chilled ammonia process. Generally, the novel systems have significantly lower energy requirements. The highest reduction is 37.3%. Another result of the comparative study is that renewable energy-based systems of carbon capturing have higher operational costs that can reach up to C$136 ton-1 of CO2 captured. Future efforts are expected to focus on reducing these costs since renewable energy-based systems are also used to co-produce chemical commodities, such as urea and ammonium bicarbonate. These high-value commodities have the potential to generate enough economic value to compensate for the operational costs of carbon capturing using ammonia as a chemical solvent.

Geographic distribution of hematopoietic cancers in the Nile delta of Egypt.

BACKGROUND: Previous evidence indicated that incidence rates of non-Hodgkin's lymphoma (NHL) are high in Egypt although little is known about risk factors. MATERIALS AND METHODS: Using data from the population-based cancer registry of Gharbiah governorate in Egypt, we assessed the 1999-2005 incidence of hematopoietic cancers (HCs) based on the ICD-O3 by age- and sex-specific urban-rural distribution. RESULTS: NHL showed the highest incidence among all HCs (11.7 per 100 000). Urban incidence of HCs was higher than rural incidence. Incidence rates of Hodgkin's lymphoma (HL) and NHL were high especially among urban males up to the 64-year age category. Rural incidence of HL and NHL was high below age 20. Among the districts of the governorate, we observed NHL incidence pattern similar to that observed for hepatocellular carcinoma because of the possible link to hepatitis C virus for both cancers. Comparison to the published HCs data from Algeria, Cyprus, and Jordan showed the highest NHL rate in Egypt than the other countries in the region. CONCLUSIONS: Future studies should define the role of environmental exposures in hematopoietic carcinogenesis in this population. In-depth studies should also investigate the role of access to health care in the urban-rural variation of HC distribution in this population.

Real-time quantitative RT-PCR and detection of tumour cell dissemination in breast cancer patients: plasmid versus cell line dilutions.

BACKGROUND: We previously developed a real-time quantitative RT-PCR technique to detect breast carcinoma cells in peripheral blood (PB). The aim of the current study was to improve cytokeratin 19 (CK19) quantification using plasmid dilutions of cloned PCR fragments to obtain a more reliable and reproducible quantification of CK19 transcripts. MATERIALS AND METHODS: PB samples of 14 stage IV breast cancer patients and 23 healthy controls were examined with RT-PCR using plasmid quantification. RESULTS: Median CK19+ copy numbers of one and 11 were detected in the control group and stage IV breast cancer patients, respectively (Mann-Whitney, P

Human papilloma virus infection and overexpression of p53 protein in bilharzial bladder cancer.

AIMS AND BACKGROUND: An association between human papilloma virus (HPV) and bladder cancer has been reported. However, the role of HPV in bilharzial bladder cancer and its prevalence have not yet been clarified. STUDY DESIGN: We investigated 50 cases for HPV types 16/18 by in situ hybridization. Also, p53 protein expression by immunohistochemistry was evaluated in 41 of the 50 cases, with correlation of these factors to clinicopathologic parameters and tumor relapse after primary treatment. RESULTS: HPV was detected in 46% of Egyptian bladder carcinomas (23/50 cases). Positivity was 47.8% for squamous cell carcinoma and 36.4% for transitional cell carcinoma. There was a possible viral-bilharzial association as 52.8% of Bilharzial cases, whereas only 12.5% of non-Bilharzial cases were HPV positive (P <0.05). P53 protein was found in 19/41 (46.3%) cases. There was a concordance between HPV and p53 in 58.5% of cases. Neither factor was related to tumor recurrence after primary treatment. CONCLUSIONS: HPV may thus be implicated in the etiology of bilharzial bladder cancer, but a definite causal relationship remains to be demonstrated. HPV together with p53 alterations work in synergy to accelerate the carcinogenic process, as there was concordance in the results of both parameters in 24/41 (58.5%) cases.

Telomerase activity in bilharzial bladder cancer. Prognostic implications.

Background: Bladder cancer is a common malignancy in Egypt and other developing countries in which infection with Schistosoma haematobium is prevalent. Bladder cancer caused by bilharziasis has different clinical and biological characters than that observed in the western world. In this study, we used the TRAP technique to estimate telomerase activity in bilharzial bladder cancer specimens and we correlated the findings with other clinical and pathological findings. Patients and methods: Bladder cancer specimens were obtained from 57 patients who underwent radical cystectomy and pathological diagnosis was obtained in all patients. Tissue samples were frozen in liquid nitrogen and stored at -80 degrees C. Telomerase activity by PCR-ELISA technique was measured using TRAP technique. Results: Our patient group included 45 males and 12 females with a median age of 49 years. The majority of our patients (35/57) have squamous histology and they have proven bilharzial history shown in the pathology specimens. Stage P3b was encountered in 29/57 patients whereas thirty-five patients have grade II tumors. The majority of our patients (41/57) were negative for pelvic nodes metastases. Telomerase activity was detected in 27/57 patients (47.4%). The mean level of telomerase was 0.85+/-0.77 in positive patients and 0.029+/-0.025 in negative patients. The expression of telomerase and its mean level in patients above age of 60, in males and in those with squamous pathology, higher grade of tumors or positive node was higher than those without but the difference did not reach statistical significance (P>0.05). Alternatively, expression was significantly higher in those with stages (P1-P3a) compared with P3b-P4a disease stages (66.6% vs. 37.1, P=0.03). Conclusion: Telomerase activity is increased in bilharzial bladder cancer although to a lesser degree than that reported for TCC in the western world, which could be explained, by different biological behavior or different assay methods. Further larger studies with more number of patients are still needed to determine its potential value for early detection and possible use as a therapeutic target.

Bladder cancer in Africa: update.

Carcinoma of the bladder is the most prevalent cancer in Egypt and in most African countries. At the National Cancer Institute (NCI), Cairo, it constitutes 30.3% of all cancers. The median age at diagnosis is 46 years, with a male preponderance of 5:1. Whether in Egypt or other African countries such as Sudan, Kenya, Uganda, Gold Coast, and Senegal, it is mostly of the squamous cell type, and arises in a background of schistosomiasis or bilharziasis. Tumors are usually advanced at the time of presentation. Bladder carcinogenesis is probably related to bacterial and human papilloma virus (HPV) infections, usually associated with bilharzial infestation. Management is mainly surgery, with 5-year survival rates after radical cystectomy increasing from 35% in the 1970s to 48% in the 1990s. The addition of adjuvant and neoadjuvant radiotherapy and chemotherapy to surgery since 1976 significantly improved both disease-free and overall survival rates. Molecular genetic studies concerning potential prognostic markers, tumorigenesis, and tumor progression in bilharzial bladder cancer are limited. However, a comprehensive detailed analysis of these factors is underway. Bilharzial bladder cancer is a preventable malignant disease. Primary prevention could be possible if the parasite is eliminated nationwide. Chemoprevention using retinoids or cyclooxygenase 2 (COX-2) inhibitors is a possible alternative. Semin Oncol 28:174-178.

Evaluation of the BTA tests for the detection of bilharzial related bladder cancer: the Cairo experience.

OBJECTIVE: To evaluate the clinical performance of the BTA stat test and the BTA TRAK assay in the diagnosis of bilharzia-related bladder cancer and to calculate a new 'Egyptian' cut-off value for the BTA TRAK (quantitative) assay. METHODS: Urine samples of 149 individuals were tested for the presence of the human complement factor H-related protein, the antigen detected by the BTA stat and BTA TRAK tests. The group consisted of 53 healthy volunteers, 20 patients with active bilharziasis, 11 patients with other urologic disorders including prostate cancer, and 65 patients with histologically proven bladder cancer. All samples were obtained prior to surgery or therapy. RESULTS: The BTA stat test was positive in 64 of 65 samples from patients with bladder cancer, for an overall sensitivity of 99%. With a BTA TRAK assay cut-off of 60 U/ml (set at 97% specificity in the healthy population), the sensitivity of the TRAK assay was 94%. There was no statistically significant difference between the sensitivities of the two BTA tests in patients diagnosed with squamous cell carcinoma and those with transitional cell carcinoma. The overall specificity of the BTA stat test was 67% ranging from 15% in patients with bilharziasis to 94% in healthy volunteers. The overall specificity of the TRAK assay was 66%, again with negative results in 15% of the patients with bilharziasis. CONCLUSIONS: The BTA stat test and TRAK tests are extremely sensitive in the detection of bladder cancer in the Egyptian population. Positive results (85%) are also observed in patients with active bilharziasis, which often leads to bladder cancer. Longitudinal follow-up of these positive cases is needed to determine whether these positive results are false or predictive of bladder cancer.

Inheritance of the 194Trp and the 399Gln variant alleles of the DNA repair gene XRCC1 are associated with increased risk of early-onset colorectal carcinoma in Egypt.

Patients under age 40 constitute 35.6% of all colorectal cancer cases in Egypt, an unusual disease pattern to which both environmental exposures and inefficient DNA repair may contribute. While a number of polymorphisms in DNA repair genes have been recently identified, their role as cancer risk modifiers is yet to be determined. In a pilot case-control study, we tested the hypothesis that polymorphisms in the gene for the DNA repair enzyme XRCC1 are associated with increased risk of colorectal cancer among Egyptians. Using a multiplex polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology, allelic variants of the XRCC1 gene at codons 194 (Arg-->Trp) (194Trp) and 399 (Arg-->Gln) (399Gln), were analyzed in DNA from lymphocytes of 48 newly-diagnosed colorectal cancer cases and 48 age- and sex-matched controls. Overall, the inheritance of 194Trp allele (Arg/Trp genotype) and 399Gln allele (combined Arg/Gln and Gln/Gln genotypes) was associated with increased colorectal cancer risk (odds ratio (OR)=2.56, 95% confidence limits (CL) 0.73-9.40, and P=0. 08 for 194Trp allele and OR=3.98, 95% CL 1.50-10.6, and P<0.001 for 399Gln allele). Interestingly, the frequencies of 194Trp and 399Gln genotypes were higher in colorectal cancer cases under age 40 than in corresponding controls, and an association between both polymorphisms and early age of disease onset was observed (OR=3.33, 95% CL 0.48-35.90, and P=0.16 for 194Trp and OR=11.90, 95% CL 2.30-51.50, and P=0.0003 for 399Gln). Analysis of the data after adjustment for place of residence indicated that the frequencies of the genotypes with the 194Trp and the 399Gln alleles were higher among urban residents (OR=3.33, 95% CL 0.48-35.90, and P=0.16 for 194Trp and OR=9.97, 95% CL 1.98-43.76, and P<0.001 for 399Gln) than among rural residents (OR=2.00, 95% CL 0.36-26.00, and P=0.30 for 194Trp and OR=1.90, 95% CL 0.50-7.53, and P=0.20 for 399Gln). These findings support our hypothesis and suggest that polymorphisms in the XRCC1 gene, in conjunction with place of residence, may modify disease risk. This first demonstration that polymorphisms in DNA repair genes may contribute to colorectal cancer susceptibility and may increase the risk of early onset of the disease opens the door for future studies in that direction.

A phase II study of gemcitabine plus cisplatin chemotherapy in advanced bilharzial bladder carcinoma.

Bilharzial bladder cancer represents a distinct clinicopathological entity. To investigate whether gemcitabine-cisplatin is also active against bladder cancer of bilharzial origin, we performed a phase II study of previously untreated patients with stage III/IV disease. Standard eligibility criteria were used. Patients received gemcitabine (1000 mg/m(2)) on days 1, 8 and 15 and cisplatin (70 mg/m(2)) on day 2 of every 28-day cycle. The 32 males and 5 females had a median age of 59 years (range: 29-81 years). Of 33 evaluable patients, 8 (24%) achieved complete responses, and 10 (30%) partial responses, for an overall response rate of 55%. 3 patients had minor responses. Responses were observed at all disease sites including lung and liver lesions. Myelosuppression was significant but manageable. Non-haematological toxicity was limited mainly to nausea and vomiting and raised liver enzymes. Thus, these data suggest that gemcitabine plus cisplatin induces high response rates in patients with bilharzial bladder cancer with a moderate toxicity profile.

Loss of Y chromosome in bilharzial bladder cancer.

Bilharzial bladder cancer is the most common malignant neoplasm in Egypt, also occurring with a high incidence in other regions of the Middle East and East Africa. In a previous study, using centromere probes specific for chromosomes 3, 4, 7-11, 16, and 17, we demonstrated that monosomy of chromosome 9 (48.4%), and numerical aberrations of chromosome 17 (19.4%) were the most common observed imbalances. The present study extends the establishment of the baseline cytogenetic profile of this type of malignancy. Interphase cytogenetics by fluorescence in situ hybridization with the use of a panel of centromere-associated DNA probes for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, X, and Y was performed on paraffin-embedded bladder specimens from 25 Egyptian patients affected with bilharzial bladder cancer. No numerical aberrations were detected in the 25 cases for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, and X. However, loss of chromosome Y was observed in 7 of the 17 male cases studied (41.2%). No significant correlation was observed between loss of the Y chromosome and any of the different clinicopathologic characteristics of these cases. These data suggest that loss of the Y chromosome is the second frequent event that can occur in bilharzial bladder cancer. A molecular genetic model of bilharzial bladder cancer is evolving.

Pathological assessment of the response of locally advanced breast cancer to neoadjuvant chemotherapy and its implications for surgical management.

The effectiveness of breast-conserving surgery for patients with locally advanced breast cancer (LABC) after neoadjuvant chemotherapy (NACT) is still a controversial issue, and variable incidences of locoregional failures have been reported. The present study was conducted to pathologically assess the response of LABC to NACT, and also to evaluate the efficacy of preoperative clinical examination and mammography in detecting these pathological changes. A total of 38 patients with LABC received NACT in the form of three cycles of fluorouracil/adriamycin/cyclophosphamide and were then subjected to a mastectomy. The residual tumors in the mastectomy specimens were measured, mapped, and compared to the pretreatment and preoperative clinical and mammographic findings for evaluation. An objective response to NACT was observed in 70.4% of the patients; however, only 26.7% of them were suitable candidates for conservative surgery. The rest of the responders showed an increased incidence of multifocality and in situ lesions localized within the original tumor-bearing area. Both clinical examinations and mammography were inadequate for the selection of candidates for breast conservation. Tumor regression by NACT is probably induced by a process of tumor segmentation. It is also associated with an increased incidence of multifocality and in situ lesions.

Chromosomal aberrations in Bilharzial bladder cancer as detected by fluorescence in situ hybridization.

Cancer of the bladder is a frequent malignancy in Egypt and other developing countries in which bladder infection with the parasite Schistosoma haematobium is common. Several epidemiological, histopathological, and clinical characteristics of cancer of the Bilharzial bladder suggest that it is distinct from bladder cancer seen in other places in the world. No numerical aberrations of chromosomes that might be specific for Bilharzial bladder carcinoma have been established. In this study, we used fluorescence in situ hybridization (FISH) with centromere-specific probes for chromosomes 3, 4, 7, 8, 9, 10, 11, 16, and 17 to detect numerical aberrations of these chromosomes in frozen-stored samples of 31 Egyptian patients affected with Bilharzial carcinoma. Among 5 types of chromosomes examined, imbalance was observed; the most common imbalance was a loss of chromosome 9 (48.4%), with numerical aberration of chromosome 17 being the second most-frequent anomaly (19.4%). The presence of such anomalies, especially losses of chromosome 9, are associated with a younger age group of patients, as well as with a lower grade tumor and negative pelvic node involvement by the disease. Fluorescence in situ hybridization analysis thus proved to be a useful method for detecting numerical aberrations of individual chromosomes, with application to touch preparations of frozen-stored tissue having the advantage of exact sampling of cancer foci. This result also suggests that the mechanism of genetic progression of bladder cancer is independent of its etiology.

Allelic instability as a predictor of survival in Egyptian breast cancer patients.

This work was designed with the purpose of determining whether the presence of allelic imbalances (AI) such as microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 2, 11, 13, and 17 in primary breast cancer could be used as prognostic indicators of patient survival. The DNA from breast cancers removed from 29 patients who were followed-up for up to five years was analyzed for MSI and LOH using a panel of 24 markers located at chromosome 2 (TPO, D2S131, D2S144, D2S171, D2S177, D2S119, D2S123, D2S147 and D2S136), chromosome 11 (C-RAS, Int-2, D11S940, D11S912), chromosome 13 (D13S289, D13S260, D13S267, D13S218, D13S263, D13S155, and D13S162), and chromosome 17 (D17S513, TP53, D17S855, and D17S785). The frequency of AI in the markers studied ranged from 30-55%, being highest for D11S912, D2S171, TP53 and D17S855. Univariate analysis showed association between overall survival rate and AI in 9 out of the 24 markers tested. Five of them were located at the area of the mismatch repair gene (MMR)-2 gene, two at 11p, one at 13q and one at 17p. Using multivariate analysis, it was observed that only pathological and clinical stage (defined as stage II or not) and AI at D2S171, D11S912, or D17STP53 generated significant predictive models for survival.

A randomized EPOCH vs. CHOP front-line therapy for aggressive non-Hodgkin's lymphoma patients: long-term results.

BACKGROUND: The value of continuous-infusion chemotherapy (EPOCH) vs. the standard CHOP combination was evaluated in 78 patients with previously untreated aggressive non-Hodgkin's lymphoma in a randomized phase III clinical trial. PATIENTS AND METHODS: The EPOCH regimen given to 38 patients consisted of the drugs etoposide (50 mg/m2), vincristine (0.4 mg/m2), and doxorubicin (10 mg/m2), all given in a continuous infusion on days 1-4. Cyclophosphamide (750 mg/m2) was administered on day 6 as i.v. bolus, while prednisone was given orally 60 mg/m2 on days 1-6. Courses were repeated every three weeks. CHOP was given to 40 patients as routinely prescribed. RESULTS: Forty-eight patients were males and thirty were females. Their ages ranged from 19-75 years (median 45 years). Forty-three (55%) had grade 2 and thirty-five (45%) had grade 3 pathologic subtype. Nine patients (12%) presented with stage I, fourteen (18%) with stage II, forty (51%) with stage III, and fifteen (19%) with stage IV disease. The different clinico-pathologic characteristics, including international index categories, were comparable in the two groups. The number of courses given ranged between 3 and 9 (median 6) for both the EPOCH and CHOP regimens. Complete remission (CR) was achieved in 19 (50%), and 27 (67%) of the 38 and 40 patients for both the EPOCH and CHOP combinations, respectively. After a median observation time of 27 months, the four-year overall and failure-free survival rates were 42% and 30% for the EPOCH and 71% and 54% for the CHOP regimen (P = 0.006 and 0.1 for the overall and FFS rates, respectively). Toxicities were comparable and were mostly of grades 1 and 2, except for hair loss, hematologic toxicities, and infectious episodes which were more common in the EPOCH group. In the EPOCH group, overall survival rates were 55% vs. 22% (P < 0.04) at four years for the low-risk (2 prognostic factors) and high-risk (> 2 factors) groups, respectively. CONCLUSIONS: Thus, it may be concluded that continuous-infusion (EPOCH) chemotherapy did not improve treatment outcome over that of the CHOP regimen for aggressive non-Hodgkin's lymphoma patients.

Diverse patterns of recognition of hepatitis C virus core and nonstructural antigens by antibodies present in Egyptian cancer patients and blood donors.

Serum samples from 429 cancer patients, 82 unpaid blood donors, and 74 paid blood donors were tested for hepatitis C virus (HCV) markers in two commercially available enzyme immunoassays (EIAs). A total of 229 of 429 (53.4%) cancer patients were positive by the two EIAs. A total of 34 of 156 (21.8%) of the blood donors were positive by the EIAs, with a higher prevalence among paid blood donors (20/74; 27%) compared with that among the unpaid blood donors (14 of 82; 17%). EIA-positive sera were tested for confirmation of the results in an immunoblot assay (LiaTek) in which reactivities to four synthetic peptides representing the HCV core protein and two synthetic peptides representing nonstructural proteins 4 and 5 were measured. Of 243 first and/or second EIA-positive samples from cancer patients, 188 (77.2%) were confirmed to be positive in the synthetic peptide immunoblot. A total of 33 of 35 (94.3%) blood donor samples were confirmed to be positive. A great diversity in reactivity patterns was seen. However, all sera from the group of paid blood donors were exclusively reactive to core peptides 1 and 2. A subset of LiaTek assay-positive samples were tested by the four-antigen RIBA-2 assay. The sera from the paid blood donors were all nonreactive. A subset of the LiaTek-positive sera was analyzed for the presence of the HCV genome by reverse transcriptase-PCR. Eleven of the 20 serum samples with reactivity to LiaTek core peptides 1 and 2 only were HCV reverse transcriptase-PCR positive, as were the majority of the sera with other reactivity patterns by the LiaTek assay. The results confirm the very high prevalence of HCV infection in Egypt. Furthermore, the results indicate that there is circulating in Egypt, particularly in the group of blood donors paid for their donation, an HCV variant which elicits an immune response that is not detected by the RIBA-2 assay.

Combination chemotherapy for advanced bilharzial bladder carcinoma.

BACKGROUND: Carcinoma of the bilharzial bladder, the most common cancer in Egyptian patients has been, until recently, largely treated by surgery. We have studied the activity of a series of single agents in phase II trials and identified a number of active agents. Here we report the results of a trial in which therapeutic combinations of the most active agents were administered in alternating cycles to patients who had never received chemotherapy. PATIENTS AND METHODS: The study included 30 patients with histologically proven inoperable (20), recurrent (5, 2 of whom subsequently developed metastases), or metastatic disease (5). There were 27 males and 3 females, with a median age of 48.5 years (range 29-65 years). Fourteen patients had squamous cell carcinoma, 12 had transitional cell carcinoma, 2 had adenocarcinoma, and the remaining 2 had undifferentiated carcinoma. Chemotherapy consisted of epidoxorubicin (120 mg/sqm i.v. d1) and vincristine (1.4 mg/sqm i.v., days 1 and 8) alternating with etoposide (100 mg/sqm i.v. infusion over 1 hour, days 1 to 5) and ifosfamide (1800 mg/sqm i.v. infusion over 2 hours, days 1 to 5). Mesna was given as a uroprotector at 40% of the ifosfamide dose at 0, 4, and 8 hours after the ifosfamide infusion. Courses were repeated every 3-4 weeks. RESULTS: Among the 22 evaluable patients, 8 (36.5%) had a partial and one (4.5%), a complete response, giving a response rate of 46%. Three more patients had responses that were less than a partial remission, and 6 patients showed disease stabilisation on chemotherapy. Toxicities were tolerable and consisted mainly of myelosuppression. Results were further analysed in relation to pathologic subtype, disease status at the start of chemotherapy, and the delivered dose intensity. No relationship was found between any of these parameters and response to therapy. CONCLUSION: Advanced bilharzial bladder cancer is relatively sensitive to combination chemotherapy, but complete remission and prolonged survival is rare in this subgroup of patients with advanced disease. Further studies will be needed to determine the relative efficacy of single agents and drug combinations.

Evaluation of in-vitro effects of recombinant human alpha 2 interferon on bilharzial urinary bladder cancer cells.

Using two different agar based double-layer culture assays, 16 bilharzial urinary bladder carcinoma samples were evaluated for the in-vitro effects of 1 hour's exposure to alpha 2 interferon at 3-log concentrations. Ten of these tumor samples were evaluable for drug sensitivity testing. In the liquid top layer dye exclusion assay, 40%, 60%, and 60% of the 10 tested tumor samples were sensitive to alpha 2 interferon 100, 1,000, and 10,000 units/ml respectively, and 25%, 25%, and 63% of 8 tumor cell suspensions were sensitive to the above drug concentrations when the human tumor colony forming assay was performed. Comparing both assays in 24 different drug measurements, there was a 71% concordance rate. All of the 7 discordant measurements were sensitive in the dye exclusion and resistant in the clonogenic assays. Thus, bilharzial bladder cancer cells are relatively sensitive to the in-vitro effect of alpha 2 interferon, especially of higher concentrations, and a phase II clinical trial deserves consideration.