Tetsuo Shibata

Treatment with rokitamycin suppresses the lethality in a murine model of Escherichia coli O157:H7 infection

The effects of rokitamycin (ROK) and levofloxacin (LEVX) were investigated in a murine model of enterohaemorrhagic Escherichia coli (EHEC) infection. After C3H/HeN mice were inoculated intragastrically with E. coli O157:H7, ROK (20mg/kg) or LEVX (1.2 mg/kg) was administered intragastrically. The death rate of the mice was noted and the faeces were collected to determine viable cell counts of EHEC and for Shiga-like toxins (SLTs) assays. After the mice were sacrificed, the kidneys and colons of some of the mice were removed for histopathological examination. The death rate of mice administered ROK (19%) was significantly lower than that of the control and LEVX-treated groups (80, 93%, respectively). Viable cell counts of EHEC in the faeces of the control and ROK-treated groups were 10(7) and 10(6) CFU/g at day 5 after the infection, respectively. LEVX reduced the bacterial count by less than 100 CFU/g at day 5. The level of SLTs in the faeces from the ROK group were lower than the LEVX-treated and control groups at day 5. The histopathological findings in the kidneys treated with LEVX showed necrotic tubular epithelial cells and those in the colon, inflammatory infiltrates. These were not seen in the ROK-treated group. These results suggested that ROK suppressed release of SLTs from the EHEC and could be useful in the treatment of EHEC infection.

Significance of urinary fibrin/fibrinogen degradation products in renal diseases measured by a highly sensitive ELISA

The urinary fibrin/fibrinogen degradation products (FDP), as sensitive indicators of various renal disorders, have been measured by several methods. For their determination, a new and highly sensitive enzyme-linked immunosorbent assay not requiring the urine concentration has been developed. The study comprised 42 patients with nonnephrotic chronic glomerulonephritis (CGN), 23 patients with primary nephrotic syndrome (NS), and 29 healthy adults. The results were as follows: (1) the content of urinary FDP in normal subjects was 10.30 +/- 9.08 ng/ml; (2) the mean level of urinary FDP in both CGN and NS groups was significantly higher than in normal subjects; (3) in the CGN group itself there was a tendency for an increase of urinary FDP during more active forms of the disease, and (4) there was a significant correlation between urinary FDP and urinary protein in the CGN group, whereas no correlation was observed in the NS group. These results suggest that the major part of urinary FDP in the CGN group derives from the increased filtration, while its origin in the NS group is not related to increased filtration only, but may also have involved intraglomerular coagulation abnormalities. The newly developed enzyme-linked immunosorbent assay can detect urinary FDP levels lower than 3.9 ng/ml. Therefore, this method can be of great value in determining the degree of abnormalities of intraglomerular coagulation and fibrinolysis in renal diseases.

Significance of Serum Fibrin/Fibrinogen Degradation Products Measured by a Highly Sensitive ELISA Method in Renal Diseases

Tetsuo Shibata, MD, Second Department of Internal Medicine, Oita Medical University, Hasama-machi, Oita 879-55 (Japan) Dear Sir, In order to clarify the abnormalities of intraglomerular coagulation and fibrinolysis in patients with various renal diseases, urinary or serum fibrin/fibrinogen degradation products (FDP) have been examined by several methods [1,2]. We previously reported the results of measurement of urinary FDP in renal diseases using a newly established sensitive enzyme-linked immunosorbent assay (ELISA) [3]. Up to now there are few reports on abnormalities of fibrinolysis, especially serum FDP, in renal diseases. This has been perhaps related with technical problems that still exist in detecting serum FDP, and especially with low sensitivity of methods used up to now. Recently, we developed a highly sensitive new method of ELISA for serum FDP using a polyclonal antibody, and utilized it to clarify abnormalities of fibrinolysis in renal diseases. The polyclonal antibody to antihuman fíbrinogen was produced by the immunization of rabbits. The horseradish peroxidase was then conjugated to antihuman fíbrinogen IgG F(ab’)2 using the modified method of Nakane [4]. Serum FDP was measured in 102 patients with various renal diseases by a two-step sandwich ELISA. The results were as follows: (1) The sensitivity of method was 0.9 ng/ml. (2) The mean ± SD of serum FDP in normal subjects was 290 ± 74 ng/ml. (3) The serum FDP levels in chronic glomerulonephritis (CGN), nephrotic syndrome (NS), chronic renal failure (CRF), diabetic nephropathy (DM) and hemodialysis patients (HD) were S-FDP (ng/ml) 10000 H 500