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Notes: Summary An increased activity of Na + /H + antiport has been reported in leukocytes and fibroblasts from insulin-dependent diabetic (IDDM) patients with nephropathy. To test whether a similar abnormality is present in fibroblasts from non-insulin-dependent diabetic (NIDDM) patients with microalbuminuria and hypertension, we examined intracellular pHi and Na + /H + antiport activity, using the pH sensitive dye 2 ′, 7 ′–bis (2–carboxyethyl–5(6)-carboxyfluorescein (BCECF), in cultured skin fibroblasts obtained from 34 NIDDM patients, divided into four groups based upon whether they had microalbuminuria or hypertension, or both: Group 1, nine NIDDM patients with microalbuminuria and hypertension. Group 2, nine NIDDM patients with hypertension and normal albumin excretion rate. Group 3, seven NIDDM patients with microalbuminuria and normal blood pressure. Group 4, nine NIDDM patients with normal blood pressure and normal albumin excretion rate. Nine normal subjects served as control group. Resting pHi was more alkaline in fibroblasts from Group 1 (7.22 ± 0.03; p 〈 0.05), Group 2 (7.21 ± 0.02; p 〈 0.05) and Group 3 (7.19 ± 0.02, p = 0.17) than in Group 4 and normal subjects. This was due to higher Vmax values of Na + /H + antiport activity in cultured fibroblasts from Group 1 (52.1 ± 5.3 mmol H + /min; p 〈 0.05), Group 2 (57.7 ± 8.3; p 〈 0.05) and Group 3 (60.6 ± 7.4, p 〈 0.05) than those from Group 4 (31.2 ± 3.6) or control subjects (31.3 ± 3.5). The intracellular pH for half-maximal activation, Hill coefficient and buffering power capacity was similar in all the groups. These data suggest that in vitro phenotypic abnormalities of long-term cultured fibroblasts from NIDDM patients with microalbuminuria and/or hypertension are likely to be, at least in part, independent of the degree of metabolic control in vivo and to be an intrinsic feature of these cells. [Diabetologia (1996) 39: 717–724]

Notes: Summary Pathogenetic mechanisms other than the quality of metabolic control may play a role in the development of diabetic nephropathy. Some cross-sectional studies have shown that elevated erythrocyte sodium-lithium countertransport (Na + /Li + CT) activity may be linked to incipient or overt nephropathy in insulin-dependent diabetic (IDDM) patients. The aim of the present work was to ascertain if high erythrocyte Na + /Li + CT activity anticipates the development of microalbuminuria in IDDM patients. Evaluation of this cation transport system was carried out in 159 normotensive, normoalbuminuric IDDM patients, who were divided into two groups: those with values above (Group A) and those with values below (Group B) the median level in the overall population (300 μmol/erythrocytes × h). A total of 79 patients in Group A and 80 in Group B underwent periodic examinations over a similar time period (5.2 years, range 3.3–7.4 years and 5.4 years, range 3.4–7.5 years, respectively). Median sodium-lithium countertransport activity was stable when evaluated after 2 and 4 years of follow-up. Only seven patients were excluded from the protocol because changes in their sodium-lithium countertransport activity placed them on the other side of the median value with respect to their baseline measurement. Thus, 152 patients completed the study (76 in Group A and 76 in Group B). Of the 76 patients in Group A, 17 developed persistent microalbuminuria (22.3 %). The number of patients in Group B showing persistent microalbuminuria was significantly lower (4 of 76; 5.2 %; p 〈 0.01). The sensitivity of erythrocyte Na + /Li + CT in predicting the development of microalbuminuria was 85 % and its specificity was 55 %. Seven patients of Group A and five of Group B developed arterial hypertension. Subjects in Group A had significantly higher mean HbA1 c values of twice yearly measurements than those in Group B (9.6 ± 1.7 vs 8.3 ± 1.7 %, p 〈 0.002, mean ± SD) despite similar daily insulin requirements. Systolic and diastolic blood pressure levels were also evaluated every 6 months and were significantly higher in the Group A than in the Group B patients, although on average within the normal range. The odds ratio for developing persistent microalbuminuria in IDDM with elevated baseline erythrocyte Na + /Li + CT activity after adjustment for gender and baseline albumin excretion rate, and mean 6 monthly plasma creatinine, HbA1 c and systolic and diastolic blood pressure levels was 4.2 (95 % confidence intervals 2.0–11.1). It was also found that the percentage of offspring having both parents with Na + /Li + CT activity above the median value was significantly higher in Group A than in Group B (Group A vs Group B: 35 vs 19 %; p 〈 0.01). On the contrary the percentage of offspring whose erythrocyte Na + /Li + CT was lower in both parents was lower in Group A than in Group B: 10 vs 38 %, p 〈 0.01). Parents of Group A offspring had arterial hypertension more frequently than those of Group B. These results indicate that erythrocyte Na + /Li + CT activity is a useful diagnostic tool in identifying normotensive, normoalbuminuric patients who may be predisposed to develop persistent microalbuminuria. This disorder in the cation transport system is associated with poor metabolic control, higher blood pressure, and male sex; it also appears to be, at least partly, genetically transmitted. [Diabetologia (1997) 40: 654–661]

Notes: Summary An increased activity of Na+/H+ antiport has been reported in leukocytes and fibroblasts from insulin-dependent diabetic (IDDM) patients with nephropathy. To test whether a similar abnormality is present in fibroblasts from non-insulin-dependent diabetic (NIDDM) patients with microalbuminuria and hypertension, we examined intracellular pHi and Na+/H+ antiport activity, using the pH sensitive dye 2′, 7′-bis (2-carboxyethyl-5(6)-carboxyfluorescein (BCECF), in cultured skin fibroblasts obtained from 34 NIDDM patients, divided into four groups based upon whether they had microalbuminuria or hypertension, or both: Group 1, nine NIDDM patients with microalbuminuria and hypertension. Group 2, nine NIDDM patients with hypertension and normal albumin excretion rate. Group 3, seven NIDDM patients with microalbuminuria and normal blood pressure. Group 4, nine NIDDM patients with normal blood pressure and normal albumin excretion rate. Nine normal subjects served as control group. Resting pHi was more alkaline in fibroblasts from Group 1 (7.22±0.03; p〈0.05), Group 2 (7.21±0.02; p〈0.05) and Group 3 (7.19±0.02, p=0.17) than in Group 4 and normal subjects. This was due to higher Vmax values of Na+/H+ antiport activity in cultured fibroblasts from Group 1 (52.1±5.3 mmol H+/min; p〈0.05), Group 2 (57.7±8.3; p〈0.05) and Group 3 (60.6±7.4, p〈0.05) than those from Group 4 (31.2±3.6) or control subjects (31.3±3.5). The intracellular pH for half-maximal activation, Hill coefficient and buffering power capacity was similar in all the groups. These data suggest that in vitro phenotypic abnormalities of long-term cultured fibroblasts from NIDDM patients with microalbuminuria and/or hypertension are likely to be, at least in part, independent of the degree of metabolic control in vivo and to be an intrinsic feature of these cells.

Notes: The aim of this study was to investigate whether the AgNOR technique could be helpful for the cytologic diagnosis of neoplastic and non-neoplastic urinary tract lesions. We analysed the AgNOR pattern in urinary cytology in samples from 70 patients. In every case the average number of silver precipitations per nucleus was counted and the range between the minimum and maximum AgNOR value calculated. Furthermore we noted whether the AgNOR precipitations had a homogeneous or heterogeneous distribution. The diseases were classified in three groups: non-neoplastic lesions, low grade and high grade carcinoma. Linear discriminant analysis (with jack-knife procedure) was performed with the AgNOR parameters as independent variables. The final diagnosis of each patient had been established by histological analysis of bladder biopsies. We obtained a correct classification in 84.3% of the cases. All patients with normal or reactive lesions were correctly classified and only two cases of low grade malignancy were erroneously diagnosed as non-malignant. Five high grade neoplasms had been classified as low grade and four low grade carcinomas had been over-diagnosed as high grade neoplasms. We conclude that a combined qualitative and quantitative AgNOR analysis can be useful in the differential diagnosis of urinary cytology.