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BACKGROUND Colorectal carcinoma (CRC) is one of the most common malignancies. In the current work, the role of arginase as a diagnostic marker in patients with recurrent CRC and colorectal liver metastases (CRCLM) was studied. METHODS Arginase activity was monitored in serum from 40 patients with primary CRC and from 100 patients with CRCLM. Blood was taken before and after patients underwent tumor resection. Studies were conducted for 3 years. RESULTS Preoperative arginase activity in serum from patients with CRC and CRCLM was much greater compared with the arginase activity in serum from healthy control blood donors. One and two cut‐off levels of increased arginase activity were observed in patients with CRC and CRCLM, respectively. After patients underwent tumor resection, the arginase activity decreased to normal values in both patients with CRC and patients with CRCLM. Activity levels remained low in patients who did not develop recurrent CRC or CRCLM (first or second). In patients who developed subsequent recurrences or metastases that appeared after surgery, during 3 years of surveillance, a significant rise in serum arginase activity was observed. The clinical prognosis for patients was worst when the postoperative serum arginase activity was very high, because those patients more often developed second liver metastases or died. CONCLUSIONS The authors conclude that the determination of serum arginase activity may be a complementary test to confirm the occurrence of CRC and may be useful for the early diagnosis of patients who develop recurrent CRC and/or CRCLM. Cancer 2002;94:2930–4. © 2002 American Cancer Society. DOI 10.1002/cncr.10563

The present work is a continuation of studies on arginase as a marker in the diagnosis of colorectal cancer liver metastases (CRCLM). The purpose of the study was the evaluation of the arginase test in comparison with other colorectal cancer tests such as CEA, CA 19-9 and biochemical markers of liver function such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The studies were conducted on blood serum from 85 patients with CRCLM obtained one to two days before tumor resection. The control group comprised 140 healthy blood donors and 81 patients with various non-malignant gastrointestinal diseases. Raised arginase activity was observed in serum of 85% of CRCLM patients, whereas elevated levels of CEA and CA 19-9 were found in 63% and 42% of patients, respectively. The combination of CEA or CA 19-9 with the arginase assay improved their sensitivity, but the sensitivity of the combined parameters was not higher than that of the arginase test itself. AST and ALT activities were increased in about 30% of CRCLM patients. The specificity of the arginase test calculated for 221 control subjects was 76%. It can thus be concluded that the determination of serum arginase activity can be helpful in the diagnosis of patients with colorectal cancer liver metastases.

Two microsatellite tandem repeated tetramers, (GACA) 4 and (CAAT) 4 , were used for Proteus mirabilis strain differentiation. The microsatellite-based PCR tests were applied for the examination of interstrain diversity for 87 P. mirabilis strains. Forty-six of the investigated strains were clinical isolates (5 were hospital isolates and 39 were outpatient clinic isolates); 42 strains were derived from the Kauffmann-Perch collection of laboratory strains. Fingerprinting done with the tetramers had a high discrimination ability [0.992 and 0.940 for (GACA) 4 and (CAAT) 4 , respectively]. The distributions of clinical isolates among well-defined laboratory strains, determined by numerical analysis (unweighted pair-group method with arithmetic averages; Dice similarity coefficient), proved their genetic similarity to reference strains in the Kauffmann-Perch collection. This analysis also indicated that it is possible to estimate some phenotypic properties of P. mirabilis clinical isolates solely on the basis of microsatellite fingerprinting.Proteus spp. are mobile gram-negative bacteria common in both the natural environment and animal or human intestinal tracts. Proteus spp. are also known etiologic agents for meningitis and numerous bacteremias (8,(20)(21)(22)(23)43). Urinary tract infections are among the most frequent bacterial infections (19), and Proteus mirabilis strains are one of the most common causes of urinary tract infections (7%), third after Escherichia coli (52%) and Enterococcus spp.(12%) (11). Such infections occur commonly among patients with structural defects of the urinary tract (6,38,39). The presence of P. mirabilis rods within a urease-induced bladder stone matrix was visualized recently (24). Moreover, some results suggest a possible etiopathogenic role of P. mirabilis in rheumatoid arthritis (9, 31), and some nosocomial transmission events have been reported (31). Because of the increasing spread and clinical significance of P. mirabilis rods (13,15,30,31,32), studies of effective methods for epidemiological investigations are of great importance.Out of the numerous types of simple sequence repeats proposed as tools for very sensitive bacterial fingerprinting (25,27,48,50,51,54), many microsatellites have been described as being useful for microbial differentiation, especially below the level of species (1,10,26,28,33,34,47,48,49,53).Most of the molecular fingerprinting methods applied for the differentiation of Proteus (35,36,44), however, are not sensitive enough for more detailed interstrain differentiation. In particular, no specific method allowing for P. mirabilis differentiation, especially below the serotype level, has been described so far.In this study, we have focused on microsatellite-based methods supplying patterns specific for particular P. mirabilis strains. The aim of the study was to verify how effective microsatellites are for P. mirabilis fingerprinting; in particular, we examined whether tandem tetramer-based PCR is applicable to Proteus strain differentiation or typing...

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