Fc gamma receptor II (CD32) on malignant B cells influences modulation induced by anti-CD19 monoclonal antibody

Antigenic modulation is one of many factors determining the effectiveness of monoclonal antibody (MoAb)-mediated therapy. To select the isotype of a CD19 MoAb most suitable for radioimmunotherapy of patients with B-cell malignancies, we studied the influence of MoAb isotype on modulation, after binding of the MoAb to different cell-line cells. The CD19-IgG1 MoAb was found to induce modulation of CD19 antigens on Daudi cell line cells more rapidly than did its IgG2a switch variant. We provide evidence that this difference in modulation rate is caused by the expression of Fc gamma receptor II (Fc gamma RII) on these cells. Experiments aimed at elucidating the mechanism of Fc gamma RII involvement in modulation induction by CD19-IgG1 showed that Fc gamma RII did not comodulate with CD19 MoAbs. However, cocrosslinking of CD19 and Fc gamma RII with CD19-IgG1 MoAb resulted in enhanced calcium mobilization in Daudi cells. This increased signal induction accompanies the enhanced capping and subsequent modulation of CD19 antigens. Because Fc gamma RII is expressed in varying densities on malignant B cells in all differentiation stages, our results have implications for the MoAb isotype most suitable for use in MoAb-based therapy of patients with B-cell malignancies.     

Genetic Contexts of blaNDM-1 in Patients Carrying Multiple NDM-Producing Strains

The carbapenem resistance determinant bla_NDM-1 has been found in various Gram-negative bacteria and upon different plasmid replicon types (Inc). Here, we present four patients within two hospitals in Pakistan harboring between two and four NDM-1-producing Gram-negative bacilli of different species coresident in their stool samples. We characterize the bla_NDM-1 genetic contexts of these 11 NDM-1-producing Gram-negative bacilli in addition to other antimicrobial resistance mechanisms, plasmid replicon profiles, and sequence types (STs) in order to understand the underlying acquisition mechanisms of carbapenem resistance within these bacteria. Two common plasmid types (IncN2 and IncA/C) were identified to carry bla_NDM-1 among the six different bacterial species isolated from the four patients. Two of these strains were novel Citrobacter freundii ST 20 and ST 21. The same IncN2-type bla_NDM-1 genetic context was found in all four patients and within four different species. The IncA/C-type bla_NDM-1 genetic context was found in two different species and in two of the four patients. Combining genetic context characterization with other molecular epidemiology methods, we were able to establish the molecular epidemiological links between genetically unrelated bacterial species by linking their acquisition of an IncN2 or IncA/C plasmid carrying bla_NDM-1 for carbapenem resistance. By combining plasmid characterization and in-depth genetic context assessment, this analysis highlights the importance of plasmids in antimicrobial resistance. It also provides a novel approach for investigating the underlying mechanisms of bla_NDM-1-related spread between bacterial species and genera via plasmids.     

Audit of multiple insulin injection regimens in a large outpatient diabetic population.

One hundred out-patients treated by multiple insulin injection regimens underwent clinical audit by retrospective analysis of their case-notes. Patients had been on multiple insulin injection therapy (MIIT) for 1.0-4.5 years (median, 3.6 years) and had had diabetes for 2 months-33 years (median, 8.7 years) at the time of starting pen therapy. Median daily insulin dose per patient did not differ significantly following stabilisation on MIIT or at latest follow-up. The median glycated haemoglobin did not change during each of the 4 years of follow-up. During the year prior to commencing MIIT the patients showed no significant alteration in body weight. Patients' weights rose significantly during each subsequent year. Median weight gains were 0.9 kg (P less than 0.005) during the first year, 1.4 kg (P less than 0.005) during the second year, 0.9 kg (P less than 0.05) during the third year and 1.4 kg (P less than 0.05) during year 4. No such weight gain was recorded in a control group of 30 patients matched for age and duration of diabetes and treated by twice daily insulin injections. Multiple insulin injection regimens used over prolonged periods in a routine clinic setting do not alter metabolic control. However, continuing weight gain appears to occur despite similar daily insulin doses.     

Metformin increases insulin sensitivity and basal glucose clearance in Type 2 (non-insulin dependent) diabetes mellitus

Abstract The effects of metformin on glycaemia, insulin and c-peptide levels, hepatic glucose production and insulin sensitivity (using the euglycaemic, hyperinsulinaemic clamp) were evaluated at fortnightly intervals in 9 Type 2 diabetic patients using a stepwise dosing protocol: Stage 1 - no metformin for four weeks; stage 2 - metformin 500mg mane; stage 3 - metformin 500mg thrice daily; stage 4 – metformin 1000mg thrice daily. Results are expressed as Mean ± SEM. Fasting blood glucose decreased from basal values (9.7 ±1.0 mmol/L) by 13% at stage 2, 34% at stage 3 and 41% at stage 4 (p<0.02 vs basal for all stages; p<0.02 stage 2 vs stage 3). Post-prandial glycaemia was significantly improved only with metformin 3000mg/day (p<0.05). Fasting, meal-stimulated and total insulin and c-peptide levels showed no change. Hepatic glucose output did not change significantly with metformin. Insulin sensitivity, measured as total glucose utilisation during hyperinsulinaemia, increased from stage 1 (10.3 ± 2.1 μmoL/kg/min) by 23% at stage 3 (p < 0.05) and by 29% at stage 4 (p < 0.02). Basal metabolic clearance of glucose increased compared to stage 1 (1.69 ±0.16 mL/kg/min) by 30% at stage 2, 53% at stage 3 and 44% at stage 4 (all p <0.02). This study demonstrates that improved efficiency of glucose utilisation, both basally and under conditions of euglycaemic hyperinsulinaemia, is the basis of metformin's antihyperglycaemic action.     

Urinary oestrogen excretion after the menopause in relation to age and body mass

We have measured urinary excretion of free immunoreactive oestrone and oestradiol and their respective glucuronides in relation to creatinine in early morning samples in 132 fit, active postmenopausal women. None of the oestrogen/creatinine ratios was significantly correlated either with age or with years since menopause. However, we did demonstrate significant positive correlations between the levels of all four oestrogens and the body mass index, weight and fat mass. These results are similar to those obtained by other workers for plasma or serum oestrogen levels. Since assessment of oestrogenic status from plasma or serum may call for several samples to allow for the rapid minute-to-minute variation in levels, urinary oestrogenic assays as described may provide a valuable non-invasive measurement of oestrogenic status. Such measurements may have a place in the identification of women at greater risk of developing symptomatic osteoporosis in later life.     

Lack of hepatic transferrin receptor expression in hemochromatosis

The major part of hepatocellular iron is derived from uptake of transferrin-bound iron by means of nonspecific fluid-phase endocytosis and specific, saturable binding on high-affinity transferrin receptors. We investigated the expression of transferrin receptors on hepatocytes in liver biopsies of 22 cases of hemochromatosis (21 primary hemochromatosis and 1 secondary hemochromatosis), using immunohistochemical demonstration of the human transferrin receptor with the specific monoclonal antibody OKT9. Fifty liver biopsies (normal and pathological) without demonstrable iron storage (Perls' stain negative) served as controls. In the controls, membranous and/or cytoplasmic transferrin receptor expression was always present on hepatocytes, albeit in variable numbers and patterns without obvious relation to the underlying liver disease. In 19 of 22 hemochromatosis cases with severe iron overload, OKT9 immunoreactivity on hepatocytes was completely absent. Three hemochromatosis cases showed few hepatocytes positive for OKT9. One showed mild iron overload, while the second, a successfully treated case, was free of iron. The remaining hemochromatosis case was a known alcoholic with severe iron overload. Since OKT9 binding to the transferrin receptor is not blocked by previous binding of transferrin, the findings show that in advanced hemochromatosis hepatocytes do not express transferrin receptors. This finding is in keeping with the inverse relation between transferrin receptor expression and exogenous iron supply in various cell cultures. These results indicate that in hemochromatosis,apparently as a result of progressive iron overload,transferrin receptor expression on hepatocytes disappears.(ABSTRACT TRUNCATED AT 250 WORDS)     

A randomized outcome evaluation of group exercise programs in long-term care institutions

BACKGROUND: Physical activity programs in nursing homes typically consist of seated, range of motion (ROM) exercises, regardless of resident abilities. The Functional Fitness for Long-Term Care (FFLTC) Program was designed not only to maintain ROM, but also to improve strength, balance, flexibility, mobility, and function. In addition, it was tailored to meet the needs of both high and low mobility residents. METHODS: The feasibility and efficacy of the FFLTC Program were evaluated with 68 residents (mean age 80) from five institutions. Persons were classified as low or high mobility and randomized into either the FFLTC program or a seated ROM program. Classes were conducted in groups of 4 to 10 residents by trained facility staff for 45 minutes, three times per week. Assessments at baseline and 4 months consisted of mobility, balance, gait, flexibility, functional capacity, and several upper and lower extremity strength measures. RESULTS: Attendance averaged 86% for the FFLTC and 79% for the ROM classes. Four months of exercise led to significant improvements in mobility (16%), balance (9%), flexibility (36%), knee (55%), and hip (12%) strength for the FFLTC group. Shoulder strength was the only improvement found for the ROM group. The ROM group significantly deteriorated in some areas, particularly hip strength, mobility, and functional ability. CONCLUSIONS: Institutionalized seniors, even those who are physically frail, incontinent and/or have mild dementia, can respond positively to a challenging exercise program. The FFLTC program demonstrated clear benefits over typical, seated ROM exercises. Moreover, with minimal training, the program can be safely delivered at low cost by institutional staff and volunteers.