Genetic characterization of the CcpA-dependent, cellobiose-specific PTS system comprising CelB, PtcB and PtcA that transports lactose in Lactococcus lactis IL1403.

Lactose metabolism is one of the most important areas of research on Lactic Acid Bacteria (LAB). In rapidly acidifying industrial Lactococcus lactis strains, lactose is transported by a lactose-specific phosphotransferase system (PTS) encoded by a plasmid. However, an alternative lactose catabolic pathway was evidenced in the plasmid-cured, and thus initially lactose-negative L. lactis IL1403. We showed that in this strain the chromosomally-encoded cellobiose-specific PTS system comprising the celB, ptcB and ptcA genes is also able to transport lactose. By expression studies in the wild type IL1403 strain and IBB550, its ccpA-deficient derivative, we demonstrated that celB, ptcB and ptcA are tightly regulated by the general catabolite repression system, whereas celB additionally requires the presence of cellobiose to be fully induced. The comparison of expression levels of sugar catabolic genes indicated that the efficiency of CcpA-mediated catabolic repression depends on conservation of the cre sequence, and that in the case of perfect matching with the cre consensus, CcpA still drives a strong repression even under non-repressing conditions.

[Thyrotropin receptor antibodies (TRAb) as a test of surgical treatment effectiveness in Graves-Basedow's diseases]. / Przeciwciala przeciw receptorom TSH jako test skutecznosci leczenia operacyjnego w chorobie Gravesa-Basedowa.

The aim of the study was to assess the relations between the concentration of antibodies against TSH receptors (TRAb) and the outcome of the surgical treatment in Graves-Basedow's disease. The studies were performed in 30 patients (age range--18-50, mean -37) operated on for Graves-Basedow's disease and in 20 healthy controls. In control group, the TRAb concentration was mean -2.75 +/- 2.06 U/l, the TSH mean -1.06 +/- 0.53 mlU/l, and FT4 mean -14.71 +/- 2.15 pmol/l. The thyroid volume was mean -14.45 +/- 2.37 ml. In the group operated on antibody concentration was determined before and 12 months after the surgery. The TSH and FT4 concentrations were also determined before and 12 months after the operation. Moreover, the size of the thyroid remnant was assessed ultrasonographically 12 months after the procedure. The results showed the effectiveness of the surgical treatment, i.e. hyperthyroidism was not observed in 22 out of 30 patients. Among these 22 patients, euthyreosis was found in 14 cases (46%) and hypothyreosis was observed in 8 cases (27%). In the euthyreosis group, the pre-operative TRAb concentration was mean -24.00 +/- 11.04 U/l. 12 months after the operation, the decreased levels of antibodies were found in 13 patients (mean -6.14 +/- 5.71 U/l). In the hypothyreosis group, the pre-operative TRAb concentration was mean -24.50 +/- 10.43 U/l. After the surgical procedure, TRAb levels were normal in all patients, the average values being 2.13 +/- 1.34 U/l. In 8 patients with recurrent hyperthyroidism (27%), TRAb concentration before the surgery was higher, mean -107.25 +/- 56.69 U/l. 12 months after subtotal strumectomy, the patients in this group still did not show normal TRAb levels (mean -54.25 +/- 51.61 U/l). Moreover, the relations between the size of the thyroid remnant and the TRAb level were evaluated. In the group with recurrent hyperthyroidism and high TRAb levels, the thyroid size (volume) left was mean -12.10 +/- 6.25 ml, in the euthyreosis group mean -5.54 +/- 2.23 ml, while in the hypothyreosis group it was mean -4.86 +/- 1.14 ml.