A perspective on protein profiling of blood

Protein profiling of blood is going to lead to huge changes in the development of biomarkers and perhaps also in producing targets for the medical treatment of cancer. Experts in this field from Los Angeles have written an outstanding mini‐review about this topic. Renal cancer has been an area of interest to all of those involved in urological oncology, particularly from the point of view of adjuvant medical treatment either to prevent metastatic disease or to treat it. Authors from Los Angeles have produced a review of great interest on this subject. There are three other reviews on important issues. Authors from Paris have written about microsatellite instability and TCC of the upper urinary tract, and authors from Bristol have written a mini‐review about the options available when considering orthotopic bladder reconstruction. Finally, authors from Dublin have written about a significant problem in renal transplantation, delayed graft function.     

Effect of repaglinide and gliclazide on postprandial control of endogenous glucose production

The effect of repaglinide and gliclazide on postmeal suppression of endogenous glucose production (EGP) has been studied using a variable-rate tracer methodology. Groups of age-, sex-, and weight-matched type 2 diabetic subjects randomized to gliclazide or repaglinide were studied after ingesting a standard mixed meal (550 kcal; 67% carbohydrate, 19% fat, 14% protein). Plasma glucose profiles were similar in each group and markedly different from that of a nondiabetic control group. Endogenous glucose production was similar basally (3.01 +/- 0.30 vs 3.06 +/- 0.19 mg/kg per minute, gliclazide and repaglinide, respectively). After glucose ingestion, EGP declined rapidly in both the groups until 30 minutes and the greatest suppression was reached earlier in the repaglinide group [0.88 mg/kg per minute at 120 minutes vs 0.77 mg/kg per minute at 210 minutes in gliclazide group (P < .05); median time, 85 vs 195 minutes, respectively (P < .05)]. The area under the curve (30-150) for EGP was significantly greater in the gliclazide group than in the nondiabetic control group (109 +/- 11 vs 198 +/- 22 mg/kg per min 2 ; P > .02) but not significantly different in the repaglinide group (153 +/- 25 mg/kg per min 2 ; P = .17). Repaglinide has minimal physiological advantage over gliclazide, but both therapies for type 2 diabetes fall far short of correcting the endocrine and metabolic abnormalities.     

Calcitonin gene-related peptide protects against hypertension-induced heart and kidney damage

Calcitonin gene-related peptide is a potent vasodilator neuropeptide that is localized in perivascular sensory nerves. To determine whether alpha-calcitonin gene-related peptide possesses protective activity against hypertension-induced end organ damage, hypertension was induced in alpha-calcitonin gene-related/calcitonin peptide knockout and wild-type mice by uninephrectomy, deoxycorticosteroid administration, and 0.9% saline drinking water. These mice were instrumented previously for long-term telemetric blood pressure recording. Control groups were sham-operated and given tap water. Mean arterial pressures were determined, and 3 weeks after initiation of each protocol, tissues were taken for histopathologic studies. The deoxycorticosteroid-salt protocol produced a significant 35% mean arterial pressure increase in both mouse strains. No pathological changes were observed in sections of aortas and femoral arteries from any of the groups studied. Likewise, heart and kidney sections from the hypertensive wild-type mice showed no pathological changes compared with their normotensive counterparts. In contrast, marked vasculitis was seen in the heart sections from the deoxycorticosteroid-salt-treated alpha-calcitonin gene-related peptide knockout mice with thickening and inflammation of the vessel walls. In addition, myocarditis and focal epicarditis with areas of myocardial necrosis were present. Kidneys of these mice exhibited prominent glomerular changes including congestion of the capillary loops, focal mesangial and crescent proliferation, and focal histocytic infiltration. Urinary microalbumin was significantly higher in the hypertensive alpha-calcitonin gene-related peptide knockout compared with hypertensive wild-type mice. These data suggest that deletion of the alpha-calcitonin gene-related peptide gene makes the heart and kidneys more vulnerable to hypertension-induced end organ damage.     

Blood glucose and risk of cardiovascular disease in the Asia Pacific region

OBJECTIVE: To assess the shape and strength of the association between usual blood glucose and cardiovascular disease (CVD) in Asian and Australasian cohorts and to determine the impact of adjusting for other determinants of CVD risk and excluding people with diabetes. RESEARCH DESIGN AND METHODS: Relative risk estimates and 95% CIs were calculated from Cox models, stratified by sex and cohort, and adjusted for age at risk on individual participant data from 17 cohort studies. Repeat measurements of blood glucose were used to adjust for regression dilution bias. RESULTS: Fasting blood glucose data were available for 237,468 participants, and during approximately 1.2 million person-years of follow-up, there were 1,661 stroke and 816 ischemic heart disease (IHD) events. Data were also available on 27,996 participants with nonfasting glucose measurements. Continuous positive associations were demonstrated between usual fasting glucose and the risks of CVD down to at least 4.9 mmol/l. Overall, each 1 mmol/l lower usual fasting glucose was associated with a 21% (95% CI 18-24%) lower risk of total stroke and a 23% (19-27%) lower risk of total IHD. The associations were similar in men and women, across age-groups, and in Asian compared with Australasian (Australia and New Zealand) populations. Adjusting for potential confounders or removing those with diabetes as baseline did not substantially affect the associations. Associations for nonfasting glucose were weaker than those with fasting glucose. CONCLUSIONS: Fasting blood glucose is an important determinant of CVD burden, with considerable potential benefit of usual blood glucose lowering down to levels of at least 4.9 mmol/l.     

Drug complexation,in vitro release and cellular entry of dendrimers and hyperbranched polymers

Highly branched, functionalized polymers have potential to act as efficient drug carrier systems. Dendrimers are ideal candidates among model hyperbranched polymers because of their well-defined structure and high density of functional groups. Using ibuprofen as a model drug, we studied the interaction between the drug and Polyamidoamine (PAMAM) dendrimers (generations 3 and 4 with --NH2 functionality) and Perstrop Polyol (generation 5, hyperbranched polyester with --OH functionality). FTIR and NMR studies suggest that ibuprofen predominantly forms a complex with PAMAM dendrimers because of the ionic interaction between the --NH2 end groups and the carboxyl group of ibuprofen. On an average, up to 78 molecules of ibuprofen could be incorporated into one molecule of PAMAM-G4-NH2 with 64 end groups. This complex is stable in deionized water and methanol. The in vitro release of ibuprofen from drug-dendrimer complex is appreciably slower compared to pure ibuprofen. The complexed drug enters A549 cells much more rapidly than pure drug suggesting that dendrimers may be able to carry the complexed drug inside cells efficiently. Hyperbranched Polyol (with 128 --OH end groups) appears to encapsulate approximately 24 drug molecules. Perhaps the lack of strong interactions between the --OH end groups and the drugs prevents complex formation.     

Covalent linking of proteins and cytokines to suture: enhancing the immune response of head and neck cancer patients

BACKGROUND: The immune system of advanced stage head and neck cancer patients is frequently suppressed. Poor immune function has been correlated with poor clinical outcome. Immunotherapeutic strategies have been previously attempted in an effort to enhance immune function and improve survival. Previous studies have shown surgical suture can be transformed into an immune stimulant capable of activating the T lymphocytes of cancer patients. The development of a process for covalently linking proteins and cytokines to suture could have enormous potential for the in vivo manipulation of the immune system. HYPOTHESIS: We hypothesize proteins and cytokines can be covalently linked to surgical suture while preserving their functional properties. STUDY DESIGN: Prospective study testing normal donor and head and neck squamous cell carcinoma (HNSCC) patient lymphocytes. METHOD: Polyester suture was acid hydrolyzed followed by reacting with 1-ethyl-3(-3-dimethylamino propyl carbodiimide) (EDAC) to create a suture-EDAC intermediate. Next, selected proteins (horseradish peroxidase [HRP] or bovine serum albumin [BSA]) or cytokines (interleukin [IL]-2 or interferon [IFN]-gamma) were reacted with the suture-EDAC intermediate to test the covalent linkage of the selected protein or cytokine to suture. Functional activity of the linked proteins was measured spectrophotometrically. The linking of cytokines to suture was tested by stimulating normal donor peripheral blood lymphocytes (PBL) or HNSCC patients' lymphocytes. The functional activity was confirmed by proliferation, enzyme linked immunoadsorbent assay (ELISA), and phenotype expression of T cells.RESULTS The conditions for optimally linking a protein to polyester suture were defined using HRP as a model protein. HRP retained its enzymatic activity. The optimal conditions for linking IL-2 or IFN-gamma were defined. The covalently linked cytokines retained their immune enhancing properties for stimulating PBL and lymph node lymphocytes (LNL) from HNSCC patients to proliferate, generate a TH1 immunologic profile of cytokines (IL-2, IL-12, IFN-gamma), and stimulate T lymphocytes. CONCLUSION: This is the first report to demonstrate that cytokines can be covalently linked to surgical sutures and retain their immune-stimulating properties. Proteins linked to suture also retained their enzymatic activity. The clinical implications of functionally active cytokines or proteins linked to surgical suture may be very significant in the future for manipulating the immune system in vivo or enhancing wound healing.     

Management of Acute Diarrhea in Emergency Room

Acute diarrhea is the second leading cause of under-five mortality in India. It is defined as the passage of frequent watery stools (>3/24 h). Recent change in consistency of stools is more important than frequency. Acute diarrhea is caused by variety of viral, bacterial and parasitic agents. The common ones are: Rotavirus, E. coli, Shigella, Cholera, and Salmonella. Campylobacter jejuni, Giardia and E. histolytica are also not uncommon. The most important concern in management of acute diarrhea in Emergency room (ER) is fluid and electrolyte imbalances and treatment of underlying infection, wherever applicable. It includes, initial stabilization (identification and treatment of shock), assessment of hydration and rehydration therapy, recognition and treatment of electrolyte imbalance, and use of appropriate antimicrobials wherever indicated. For assessment of hydration clinical signs are generally reliable; however, in severely malnourished children sunken eyes and skin turgor are unreliable. Oral Rehydration Therapy is the cornerstone of management of dehydration. Intravenous fluids are not routinely recommended except in cases of persistent vomiting and/or shock. Majority of cases can be managed in ER and at home. Hospitalization is indicated in infants <3 mo, children with severe dehydration, severe malnutrition, toxic look, persistent vomiting and suspected surgical abdomen. Supplementations with zinc and probiotics have been shown to reduce severity and duration of diarrhea; however evidence does not support the use of antisecretary, antimotility and binding agents. Education of parents about hand hygiene, safe weaning and safe drinking water etc., can help in reducing incidence of this important health problem in the country.     

Efficacy and safety of dofetilide in patients with atrial fibrillation and atrial flutter

Background  Dofetilide, an I_Kr blocker has been demonstrated to be effective in terminating persistent atrial fibrillation and flutter (AF/AFL), and in maintaining sinus rhythm after direct current cardioversion (CV). It is not known, however, whether pharmacological conversion with dofetilide predicts maintenance of sinus rhythm. In addition, there is limited information comparing the efficacy of dofetilide in persistent versus paroxysmal AF/AFL. Methods and Results  Eighty consecutive patients with AF/AFL (51 persistent, 29 paroxysmal) admitted for initiation of dofetilide were studied. Termination of persistent AF/AFL occurred in 61% of patients while 39% required CV. After 21 ± 19 months of follow-up, 37% of patients with persistent AF/AFL were free of recurrence. Acute conversion with dofetilide did not predict long term efficacy. Dofetilide was more effective in maintaining sinus rhythm in patients with AFL (65%) than in those with AF (25%) (p < 0.05). Dofetilide was more likely to maintain sinus rhythm in patients with persistent than paroxysmal AF/AFL (37 vs. 14%; p < 0.05). Torsades de Pointes developed in two patients despite careful dosing and monitoring of QT changes. Conclusions  Dofetilide is more effective in patients with persistent than in those with paroxysmal AF/AFL. Importantly, short-term response does not necessarily predict long-term efficacy. Significant proarrhythmia can occur even with careful in-hospital monitoring. Dr. Banchs and Dr. Wolbrette contributed equally to this study. Presented in abstract form at the XIII World Congress on Cardiac Pacing and Electrophysiology; December 3, 2007; Rome and published in abstract form (Giornale Italiano di Aritmologia e Cardiostimolazione 2007;10(3):26).