Evaluation of the effect of protamine on human prostate carcinoma PC-3m using contrast enhanced Doppler ultrasound

PURPOSE

We evaluated the ability of contrast enhanced Doppler ultrasound (CEDU) to demonstrate changes in tumor vascularity during angiogenesis inhibitive therapy in PC-3m human prostate carcinoma.

MATERIALS AND METHODS

Pieces of human prostate carcinoma PC-3m tumor (Institute of Urology, Beijing University, Beijing, People's Republic of China) were transplanted subcutaneously into 48 male BALB/C nude mice (Center of Animal Quarantine, Beijing, People's Republic of China). Protamine (Shanghai Biochemistry Pharmaceutical Co., People's Republic of China) was injected subcutaneously as an angiogenesis inhibitor. The animals were randomly divided into 3 groups according to protamine dose. The color flow signal-pixel rate (SPR) of the images was calculated using the number of pixels showing color Doppler signals as a ratio of the total number of pixels covering the lesion.

RESULTS

The SPR of the high and low dose groups were significantly lower than that of the control group (p <0.01). Mean SPR +/- SD in the 3 groups was 0.09 +/- 0.05, 0.11 +/- 0.05 and 0.22 +/- 0.10, respectively. SPR correlated significantly with microvessel density (r = 0.86 to 0.94, p <0.01).

CONCLUSIONS

CEDU can effectively reveal the change in vascularity in a tumor that was treated with protamine. In addition to microvessel density, CEDU may become one of several independent prognostic indexes of angiogenesis inhibitor therapy.

Low molecular weight protamine as an efficient and nontoxic gene carrier: in vitro study

BACKGROUND

The structural similarity between low molecular weight protamine (LMWP), prepared by enzymatic digestion of protamine, and HIV-TAT protein transduction peptide suggested the feasibility of LMWP as an efficient carrier for delivering therapeutic genes while alleviating the cytotoxicity of currently employed gene carriers.

METHODS

LMWP was prepared by enzymatic digestion of protamine with thermolysine. The prepared LMWP peptide and TAT peptide, as well as their complexes with plasmid DNA (pDNA), were examined for cellular uptake behaviors by using confocal microscopy and flow cytometry. The complexation of pDNA and LMWP was monitored by gel retardation test as well as size and zeta potential measurements, and was then further assessed by DNase I protection assay. The transfection efficiency of pDNA/LMWP was examined by varying the pDNA content and charge ratio in the complex, and then compared with that of pDNA/PEI. Cytotoxicity induced by pDNA/LMWP and pDNA/PEI was also examined.

RESULTS

Prepared LMWP showed similar transcellular localization behavior and kinetics to those of TAT, and efficiently transferred the pDNA into nucleus and cytoplasm in a short time period. The size and zeta potential of the pDNA/LMWP complex were 120 nm and 30 mV, respectively, which were adequately suitable for cellular uptake. After forming the complex, LMWP appeared to effectively protect pDNA against DNase I attack. The pDNA/LMWP complex showed significantly enhanced gene transfer than both naked pDNA and the pDNA/PEI complex, while exhibiting a markedly reduced cytotoxicity than that of the pDNA/PEI complex.

CONCLUSIONS

The present study suggested that LMWP could be a useful and safe tool for enhancing delivery of bioactive molecules and therapeutic DNA products into cells when applied in gene therapy.

Continuous renal replacement therapies: anticoagulation in the critically ill at high risk of bleeding

BACKGROUND

The ongoing necessity for systemic heparinization is a well-known disadvantage of continuous renal replacement therapies (CRRT), and alternative methods of anticoagulation may be required. Our aim was to evaluate, in patients with a high risk of bleeding, the possibility of an acceptable filter life with non-anticoagulation CRRT and, in case of early filter failure, the efficacy and safety of bedside monitored regional anticoagulation with heparin and protamine.

METHODS

Fifty-nine patients underwent CRRT for acute renal failure (ARF) following cardiac surgery. Patients who fulfilled one of the following criteria were selected for non-anticoagulation CRRT: spontaneous bleeding, aPTT > 45 sec, thrombocytopenia and recent surgery (< 48 hr). Filter life < 24 hr without anticoagulation was the cut-off point for starting the regional anticoagulation CRRT. Heparin was infused pre-filter and protamine post-filter at an initial ratio of 1 mg protamine:100 IU heparin. The ratio was adjusted to achieve a patient aPTT < 45 sec and a circuit > 55 sec.

RESULTS

Twenty-two (37.3%) patients had been selected for non-anticoagulation. Of them, 12 patients continued to receive non-anticoagulation (filter life: 38.3 +/- 30.5 hr) while 10 switched to regional anticoagulation (filter life: 38.6 +/- 25 hr). During regional anticoagulation no statistical difference was found between baseline aPTT (36.7 +/- 6.4 sec) and patient aPTT (41.5 +/- 12.6 sec) while circuit aPTT (77.7 +/- 43.3 sec) was significantly higher than patient aPTT (p < 0.0001). The probabilities of the circuits remaining free from clotting after 24, 48 and 72 hr were: a) non-anticoagulation: 55.5%, 30.1% and 16.6%, b) regional anticoagulation: 76.2%, 39.6% and 19.8%. There was no rebound anticoagulation observed after regional anticoagulation CRRT ended.

CONCLUSIONS

Non-anticoagulation CRRT allowed an adequate filter life in most patients with a high risk of bleeding for prolonged aPTT and/or thrombocytopenia. Despite concerns regarding the need for careful monitoring, regional anticoagulation with heparin and protamine can be considered as a safe and valid alternative when non-anticoagulation is unsuitable because of early filter failure.

Single-dose tranexamic acid reduces postoperative bleeding after coronary surgery in patients treated with aspirin until surgery

Tranexamic acid reduces postoperative bleeding after coronary artery bypass grafting. We evaluated the effects of a single dose of tranexamic acid given immediately before cardiopulmonary bypass (CPB) in patients treated with aspirin until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel-group trial. Eighty patients were included and divided into two groups: one group received tranexamic acid 30 mg/kg, and one group received placebo (0.9% NaCl) as a bolus injection before CPB. Postoperative blood loss was recorded for 16 h. Transfusions of blood products were recorded for the whole hospital stay. Transfusions of packed red cells were given when the hematocrit value was less than 20% during CPB and less than 25% after surgery. The patients in the tranexamic acid group had significantly less postoperative bleeding compared with the patients in the placebo group (mean [SD]) (475 [274] mL versus 713 [243] mL; P < 0.001). An effective inhibition of fibrinolysis was found in patients receiving tranexamic acid. Tranexamic acid reduces postoperative bleeding in coronary artery bypass grafting patients treated with aspirin until the day before surgery.

IMPLICATIONS

Continuation of aspirin medication until the day before coronary artery bypass grafting may increase postoperative bleeding. The administration of a single dose of tranexamic acid (30 mg/kg) immediately before cardiopulmonary bypass significantly reduced postoperative bleeding and inhibited fibrinolysis in these patients.

The use of specific antidotes as a response to bleeding complications during anticoagulant therapy for venous thromboembolism

When a bleeding complication occurs during therapy with heparin or vitamin K antagonists, there is an option to give a specific antidote. Several new anticoagulants have been developed that are likely to have some risk of bleeding complications, for which no specific antidotes are available. Interestingly, it is unknown how often the use of an antidote is necessary in clinical practice. We investigated 1877 patients treated for venous thromboembolism included in three large clinical trials, of which 181 (9.6%) had a total of 225 adjudicated bleeding episodes; 46 hemorrhages being designated as major. Some form of antidote was given to 26 (14.4%) patients with a hemorrhage. Of the patients with at least one major hemorrhage, 19 (41.3%) received an antidote. Vitamin K was given to 23 (1.2%) patients, one (0.05%) patient received protamin sulfate and seven (0.4%) patients received fresh frozen plasma. The use of antidotes was comparable for initial and long-term treatment. Antidotes were statistically significantly more frequently given in Canada as compared to other participating countries. Vitamin K was more frequently given in case of a higher international normalized ratio value. Although antidotes against anticoagulant treatment are widely available, our analysis shows that in only a very small number of patients a direct, or slow-acting antidote to reverse the anticoagulant effect was used.

Heparin reversal in off-pump coronary artery bypass surgery: complete, partial, or no reversal?

Several clinical studies have reported that avoiding cardiopulmonary bypass reduces postoperative bleeding. The purpose of this study is to verify that protamine during off-pump coronary artery bypass surgery produces significant reduction of postoperative bleeding. Sixty consecutive patients undergoing off-pump coronary artery bypass surgery were prospectively randomized in three groups: Group A received 1 mg of protamine every 100 IU of heparin, Group B 0.5 mg of protamine every 100 IU of heparin, and Group C none. The three groups were analyzed for differences in preoperative cardiac function, pre-, intra-, and postoperative coagulation profile, intraoperative variables, and postoperative bleeding. In the three study groups, no statistically significant difference was found in preoperative cardiac function, pre- and intraoperative coagulation profile, and prothrombin time, activated partial thromboplastin time, platelet count in the first postoperative day. In Group A, total postoperative bleeding, use of packed red blood cells, and mild pericardial effusion prevalence at discharge were significantly lower only when compared to Group C, but they were not significantly different when compared to Group B. In off-pump coronary artery bypass surgery, heparin should be reverted with protamine, otherwise the postoperative bleeding risk might increase. Partial heparin reversal might not increase postoperative bleeding risk, but it may reduce dose-dependent protamine adverse effects.

Assessment of protamine-induced thrombosis of tumor vessels for cancer therapy using dynamic contrast-enhanced MRI

Since the role of angiogenesis in cancer development has been recognized, the study of anti-angiogenic or anti-vascular therapeutic agents has become increasingly important for cancer treatment. Selective thrombosis is one approach towards this goal. Since many types of carcinoma accumulate large numbers of degranulating mast cells which will release heparin, intravenously injected protamine may bind to heparin, neutralize its anti-coagulant effect and induce thrombosis. In this work we studied the formation of thrombosis by using dynamic contrast enhanced MRI. The enhancement kinetics of the contrast medium measured before and after protamine treatment were compared to assess the thrombotic effect. The underlying concept was that if the vessels became clotted, the subsequently injected contrast medium could not be delivered into the tissue to cause enhancement. In addition to the tissue-specific changes, protamine may also induce systemic effect in the host. The therapy-induced changes measured in tumors were compared to changes in normal tissues: liver, kidney, and especially the muscle adjacent to tumor. The results showed that protamine induced pronounced changes in the tumor. However, the degree of change measured by MRI was not associated with the results of semiquantitative assessment of thrombosis assessed by histology, perhaps due to the heterogeneous nature of the tumor and the difficulty in sampling sufficient regions histologically. The protamine-induced temporal effects were also studied. We demonstrated that protamine could induce selective thrombosis in tumors, and that the effect could last for several hours. Dynamic contrast-enhanced MRI can serve as a suitable means to investigate the mechanism of this novel approach to induce selective thrombosis for anti-vascular cancer therapy.

Anticoagulation therapy in acute renal failure extracorporeal treated patients

In extracorporeal techniques, as used for Acute Renal Failure (ARF) treatments, blood is constantly exposed to foreign surfaces. These foreign surfaces include the catheter(s), blood tubings, the dialyser membrane and all artificial materials used for such techniques in general. Blood begins to clot as soon as it strikes a foreign surface. The foreign surface initiates the clotting process. The extracorporeal circuit is prone to clotting during acute treatments unless some form of anticoagulation is employed. On the other hand, this specific group of patients is often at increased risk of bleeding (cfr. Post-operative patients and post-renal-transplant patients, patients with Multiple Organ Failure (MOF) often including liver disturbances). It should be kept in mind that patients with renal failure have a defect in platelet function resulting in altered platelet-vessel wall interaction. Over time, as the extracorporeal treatment progresses, the platelets become more adhesive or sticky. The blood becomes more likely to clot. Performing effective therapy with low bleeding risk in ARF patients is a challenge requiring knowledge, skills and experience.

Effects of a fixed mixture of 25% insulin lispro and 75% NPL on plasma glucose during and after moderate physical exercise in patients with type 2 diabetes

OBJECTIVE

To compare the plasma glucose (PG) response with a fixed mixture of 25% insulin lispro and 75% NPL (Mix25), prior to a meal and 3 h before exercise, to human insulin 30/70 (30/70) in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Thirty-seven patients were treated in a randomized, open-label, 8-week, two-period crossover study. Mix25 was injected 5 min before breakfast and dinner throughout the study, as was 30/70 on inpatient test days and on outpatient dose titration days. Following the 4-week outpatient phase, patients were hospitalized, and exercised at a heart rate of 120 beats/min on a cycle ergometer two times for 30 min, separated by 30 min rest, starting 3 h after a 339 kcal breakfast.

RESULTS

The 2-h postprandial PG was significantly lower with Mix25 ((mean +/- SEM) 10.5 +/- 0.4 mmol/l vs 11.6 +/- 0.4 mmol/l; p = 0.016). Maximum decrease in PG from onset of exercise to end of exercise was significantly less with Mix25 (-3.6 +/- 0.29 mmol/l vs -4.7 +/- 0.31 mmol/l; p = 0.001). The maximum decrease in PG over 6 h, after exercise onset, was significantly less with Mix25 (-4.3 +/- 0.4 mmol/l vs -5.9 +/- 0.4 mmol/l; p < 0.001). The frequency of hypoglycemia (blood glucose (BG) < 3 mmol/l or symptoms) during the inpatient test was not different between treatments. During the outpatient phase, the frequency of patient-recorded hypoglycemia was significantly lower with Mix25 (0.7 +/- 0.2 episodes/30 d vs 1.2 +/- 0.3 episodes/30 d; p = 0.042).

CONCLUSIONS

Mix25 resulted in better postprandial PG control without an increase in exercise-induced hypoglycemia. The smaller decrease in PG during the postprandial phase after exercise may suggest a lower risk of exercise-induced hypoglycemia with Mix25 than with human insulin 30/70, especially for patients in tight glycemic control.

Life threatening cardiopulmonary failure in an infant following protamine reversal of heparin after cardiopulmonary bypass

Life threatening cardiopulmonary failure following protamine reversal of heparin after cardiopulmonary bypass (CPB) was reported to occur in adults but rarely in children. Atrial septal defect closure was performed in a 6-week-old infant erroneously suspected to suffer from right atrial thrombosis in addition. Protamine administration after CPB led to critical pulmonary hypertension and severe haemorrhagic pulmonary oedema resulting in severe hypoxia. Inhaled nitric oxide, together with high frequency oscillation ventilation supplemented by intravenous prostacycline, enabled complete recovery of cardiopulmonary and neurological function. Life threatening cardiovascular compromise after intravenous protamine can occur even in young infants which then require challenging paediatric critical care.

Alternatives to unfractionated heparin for anticoagulation in cardiopulmonary bypass

Despite the progress made in the development of cardiopulmonary bypass (CPB) equipment, systemic anticoagulation with unfractionated heparin and post-bypass neutralization with protamine are still used in most perfusion procedures. However, there are a number of situations where unfractionated heparin, protamine or both cannot be used for various reasons. Intolerance of protamine can be addressed with extracorporeal heparin removal devices, perfusion with (no) low systemic heparinization and, to some degree, by perfusion with alternative anticoagulants. Various alternative anticoagulation regimens have been used in cases of intolerance to unfractionated heparin, including extreme hemodilution, low molecular weight heparins, danaparoid, ancrod, r-hirudin, abciximab, tirofiban, argatroban and others. In the presence of heparin-induced thrombocytopenia (HIT) and thrombosis, the use of r-hirudin appears to be an acceptable solution which has been well studied. The main issue with r-hirudin is the difficulty in monitoring its activity during CPB, despite the fact that ecarin coagulation time assessment is now available. A more recent approach is based on selective blockage of platelet aggregation by means of monoclonal antibodies directed to GPIIb/IIIa receptors (abciximab) or the use of a GPIIb/IIIa inhibitor (tirofiban). An 80% blockage of the GPIIb/IIIa receptors and suppression of platelet aggregation to less than 20% allows the giving of unfractionated heparin and running CPB in a standard fashion despite HIT and thrombosis. Likewise, at the end of the procedure, unfractionated heparin is neutralized with protamine as usual and donor platelets are transfused if necessary. GPIIb/IIIa inhibitors are frequently used in interventional cardiology and, therefore, are available in most hospitals.

Evaluation of post-cardiopulmonary bypass coagulation disorders by differential diagnosis with a multichannel modified thromboelastogram: a pilot investigation

We assessed a modified multichannel thromboelastogram for differentiation of the causes of coagulopathy after cardiopulmonary bypass and its suitability as a therapy guide. Thirty adult patients undergoing surgery with cardiopulmonary bypass, who revealed a coagulopathy as observed by a prolonged activated clotting time of >150 sec after the application of protamine, were enrolled. Therapy was based on the results obtained by the computerized four-channel thromboelastogram with baseline, heparinase (2 IU/mL), heparinase/abciximab (5 microg/mL), and heparinase/fresh frozen plasma (25%) channels. The mean activated clotting time before therapy was 162.2+/-7.8 sec. Based on differential diagnosis with the modified multichannel thromboelastogram, two patients received protamine (30 mg), five desmopressin (0.4 microg/kg), 19 patients three units of fresh frozen plasma, two patients platelet transfusions, and two patients both protamine (30 mg) and three units of fresh frozen plasma. After therapy, there was a significant (p < .01) decrease of the activated clotting time to a mean value of 127+/-8.3 sec. Therapy based on the synoptic modified multichannel thromboelastogram analysis provides a guide for effective therapy of coagulopathy. However, elaboration is desirable, and larger clinical trials are necessary for a final evaluation of the protocol.

Clinical use of heparin-coated cardiopulmonary bypass in coronary artery bypass grafting

Clinical handling, risk and benefit of a heparin-coated cardiopulmonary bypass system combined with reduced systemic heparinization in coronary bypass surgery was investigated in a prospective, randomized clinical study. 243 patients (Pts.) were divided into 3 groups: group A (n = 83) had a standard uncoated extracorporeal circulation (ECC) set, and systemic heparin was administered in an initial dose of 400 IE/kg body weight. During ECC activated clotting time (ACT) was kept > or = 480 sec. Group B (n = 77) had the same ECC set completely coated with low-molecular-weight heparin; i.v. heparin was given in the same dose as in group A, ACT was kept at the same level. Group C (n = 83) had the same coated ECC set as group B, but i.v. heparin was reduced to 150 IE/kg, and was set to be > or = 240 sec during ECC ACT. The same circulatory components were used in all 3 groups including roller pumps, coronary suction and an open cardiotomy reservoir. In the postoperative clinical course, recovery was not significantly different between groups, especially with respect to organ dysfunction; but there was significantly reduced postoperative bleeding where heparin-coated ECC and low-dose systemic heparinization were both used. This circulatory technique was also associated with a distinctly lower need for postoperative blood replacement. We conclude that heparin-coated extracorporeal circulation combined with either full-dose or reduced systemic heparinization can be used effectively with the same standard equipment and procedures as in uncoated technology. Combination with low-dose i.v. heparin leads to significantly decreased blood loss and less need for blood replacement.

[Use of Organon, a synthetic heparinoid, in two cardiopulmonary bypass procedures in the same patient sensitive to heparin]

We report the case of a patient who underwent two cardiopulmonary bypass (CPB) procedures with Orgaran because of heparin-induced thrombocytopenia. A 38 years-old man with ischemic mitral insufficiency was operated for coronary artery bypass and valvular replacement. The CPB was carried out with heparin. Heparin-induced thrombocytopenia occured and was proven immunologically. Two months later, a new valvular replacement was performed because of paravalvular leak due to endocarditis. The Orgaran-CPB protocol was as follows: 5,000 units before cardiopulmonary bypass, 5,000 units in the priming volume, anti-Xa level between 0.9 and 1.1 units/mL, with injection of 1,500 units if necessary, no administration of protamine. One month later, a new valvular replacement was necessary and performed with the same protocol using Orgaran. No bleeding or thrombotic complication occurred. Orgaran is a safe and reliable anti-thrombotic substitute if anti-Xa activity is closely monitored.

The economic value of a new insulin preparation, Humalog Mix 25. Measured by a willingness-to-pay approach

OBJECTIVE

To measure the economic value of a new insulin formulation consisting of rapid-acting insulin lispro and intermediate-acting neutral protamine lispro in a 25:75 ratio (Humalog Mix 25).

DESIGN AND SETTING

A cost-benefit analysis using a consumer-based willingness-to-pay (WTP) approach was used. The study sample consisted of 80 Canadian taxpayers randomly selected from Ontario and Quebec. After background information on the differences between Humalog Mix 25 and human 30/70 insulin were presented, respondents were asked what their preferred product would be if they were diagnosed with diabetes mellitus. Respondents were then asked the maximum premium that they would pay per month in the form of a user's fee for the insulin of their choice.

STUDY PERSPECTIVE

Canadian taxpayer perspective.

MAIN OUTCOME MEASURES AND RESULTS

The WTP survey instrument was simple to administer and easily understood by participants. Approximately 84% of the sample of taxpayers preferred to use Humalog Mix 25 rather than human 30/70 insulin and were willing to pay for it (p = 0.012). They were willing to pay a mean of $Can35.28 [95% confidence interval (CI): $Can27.50 to $Can43.07] per month for the benefits offered by Humalog Mix 25, which was at least 2-fold higher than the incremental monthly cost of the drug (1999 values).

CONCLUSIONS

The results of the study revealed that Canadians prefer to use Humalog Mix 25 instead of human 30/70 insulin, and they would be willing to pay for it. Compared with other drugs, this overall net gain suggests that Humalog Mix 25 represents good value for money and should be considered for reimbursement by government formularies and other third-party payers.

Effect of glucagon on glucose production, lipolysis, and gluconeogenesis in familial hyperinsulinism

We present an infant with severe familial hyperinsulinism in whom glucose production rate, lipolysis, and gluconeogenesis from glycerol were measured by use of glucose and glycerol labelled with stable isotopes. Administration of a single dose of glucagon (0.1 mg/kg) caused an increase in glucose production rate by near 140% from 4.2 to 10.1 mg.kg-1.min-1. The rate of appearance of glycerol, reflecting the rate of lipolysis, decreased from 15.1 to 12.6 micromol. kg-1.min-1. The amount of glycerol converted to glucose by gluconeogenesis was 9.1 micromol.kg-1.min-1 before and 10.5 micromol. kg-1.min-1 after glucagon administration. We conclude that the marked rise in glucose production rate was mainly the result of increased glycogenolysis. Following the trial, the child was started on long-acting (zinc-protamine) glucagon which made it possible to discontinue intravenous treatment with glucose.

Hemostatic effects of low-dose protamine following cardiopulmonary bypass

Twenty-eight patients undergoing cardiac surgery were prospectively studied and were assigned to two groups. The patients received 0.8- (Group L) or 2.0-fold (Group H) dose of protamine for the neutralization after cardiopulmonary bypass (CPB) which was determined by Hepcon HMS(R) assay system in which the reagent chamber containing the concentration of protamine that completely neutralized the heparin had the shortest clotting time. Mean dose of protamine was 1.60 +/- 0.50 mg kg(-1) in Group L, and 3.56 +/- 1.48 mg kg(-1), respectively. Activated clotting times (ACT) were comparable between the two groups through this study period. In Group H, platelet counts significantly decreased to 69% of that before protamine administration, and plasma platelet factor 4 level significantly increased to approximate 2-fold of that before protamine administration just after protamine administration, respectively. However, these phenomena were not observed in Group L. In addition, these hemostatic changes occurred transiently just after protamine administration. We conclude that the low-dose protamine may prevent transient platelet depletion following CPB. Low-dose protamine can neutralize anticoagulation effect of heparin sufficiently and may mitigate protamine-induced platelet dysfunction.

Optimized basal-bolus therapy using a fixed mixture of 75% lispro and 25% NPL insulin in type 1 diabetes patients: no favorable effects on glycemic control, physiological responses to hypoglycemia, well-being, or treatment satisfaction

OBJECTIVE

To investigate the effects of a multiple injection regimen with a mixture of 75% lispro and 25% intermediate-acting insulin (lispro high mixture [HM]) before meals on glycemic control, physiological responses to hypoglycemia, well-being, and treatment satisfaction.

RESEARCH DESIGN AND METHODS

We studied 35 type 1 diabetes patients. After an 8- to 10-week lead-in period, patients were randomized to HM or human regular insulin therapy for 12-14 weeks. During the lead-in and treatment periods, HbA1c levels and hypoglycemic frequencies were measured, and patients completed the Well-Being Questionnaire and the Diabetes Treatment Satisfaction Questionnaire. In 19 patients, responses to hypoglycemia were tested during stepped euglycemic-hypoglycemic clamps.

RESULTS

HM treatment improved postprandial glycemia but had no effect on HbA1c, frequency of hypoglycemia, well-being, or treatment satisfaction. During experimental hypoglycemia, HM therapy was associated with a slightly lower total adrenaline response and a higher autonomic symptom threshold (i.e., the autonomic symptom response occurred at a lower blood glucose level) than human regular insulin therapy. We speculate that this effect resulted from an accumulation of insulin during the night.

CONCLUSIONS

Multiple injection therapy with HM rather than human regular insulin before meals does not offer advantages regarding glycemic control, frequency of hypoglycemia, well-being, or treatment satisfaction. In addition, this regimen causes an attenuation of the adrenaline and autonomic symptom responses to hypoglycemia.

Early mobilization after protamine reversal of heparin following implantation of phosphorylcholine-coated stents in totally occluded coronary arteries

Immediate removal of the femoral artery sheath after coronary angioplasty may allow rapid mobilization and reduces the number of in-hospital days. We studied the early and 1-month clinical and angiographic follow-up of patients having heparin reversed with protamine after implantation of phosphorylcholine-coated metal (Divysio) stents, followed by removal of the femoral artery sheath. Fifty patients (37 men, mean age 59 +/- 10 years) with stable angina pectoris and a single totally occluded artery (1 unprotected left main stem, 15 left anterior descending, 11 left circumflex, 23 right) underwent coronary angioplasty. Antithrombotic medication was salicylic acid 75 to 160 mg before, heparin bolus 7,500 IU during, and protamine sulfate 25 mg and oral ticlopidine 250 mg after the procedure. Angiography was performed after 30 minutes and at 1 month. The mean number of stents was 1.4 +/- 0.6/lesion, with a mean final diameter of 2.69 +/- 0.40 mm. One stent thrombus was detected after 30 minutes and was treated with balloon dilatation. One patient underwent emergency bypass surgery for non-stent-related problems. Forty-six patients were mobile after 5 hours, and 2 after >5 hours. At 1 month there had been no major coronary end points, rehospitalizations, groin bleeding, or more thrombi. One episode of transient pulmonary edema occurred after protamine injection. Thirty-eight patients (79%) had no angina at 1 month, maximal bicycle exercise capacity increased from 128 +/- 42 to 160 +/- 45 W (p <0.05), and left ventricular ejection fraction increased from 63% to 68% (p <0.05). Thus, reversal of heparin with protamine sulfate after implantation of a phosphorylcholine-coated stent enables early mobilization. This approach seems safe in patients with 1 -vessel total occlusions and angioplasty could be performed as an outpatient procedure.

Improved postprandial glycemic control with Humalog Mix75/25 after a standard test meal in patients with type 2 diabetes mellitus

OBJECTIVE

This double-blind study was designed to compare the postprandial glucodynamic profile of Humalog Mix75/25, a new premixed insulin analogue containing 75% neutral protamine lispro and 25% insulin lispro with that of human insulin 70/30 (70% neutral protamine Hagedorn insulin and 30% regular human insulin) in patients with type 2 diabetes mellitus.

BACKGROUND

Insulin lispro Mix75/25 (Mix75/25) is the first available insulin formulation in which both the rapid-acting and basal components are insulin analogues.

METHODS

This randomized, multicenter, double-blind, crossover study monitored patients' postprandial glucodynamic response to Mix75/25 and human insulin 70/30 (70/30) after a standard test meal. Eighty-four patients with type 2 diabetes participated in this study and were randomly assigned to 1 of 2 treatment sequence groups. Patients received an identical test meal on 4 occasions, completing 2 test meals for each treatment. Equal doses of Mix75/25 or 70/30 were administered 5 minutes before each of the 2 test meals, with doses individualized for each patient. Blood samples were collected for 4 hours after the meal for measurement of plasma glucose. From these plasma glucose measurements, fasting plasma glucose, 2-hour postprandial glucose (2pp), 2-hour postprandial glucose excursion (2pp(ex)), maximum glucose excursion (Gex(max)), the area under the glucose concentration versus time curve from 0 to 4 hours (AUC4), and the area under the glucose excursion versus time curve from 0 to 4 hours (AUCex4) were calculated.

RESULTS

Because of significant differences in the baseline fasting plasma glucose levels between Mix75/25 and 70/30 (Mix75/25: 8.9+/-2.2 mmol/L [160.2+/-39.6 mg/dL]; 70/30: 8.6+/-1.9 mmol/L [154+/-34 mg/dL), analyses of the excursion parameters provide a truer comparison of the glucodynamic response between insulin formulations. Mix75/25 resulted in significantly lower values for 2pp(ex) (3.35+/-2.28 vs 4.13+/-2.26 mmol/L), Gex(max) (4.51+/-1.88 vs 5.19+/-1.98 mmol/L), and AUCex4 (8.01+/-7.02 vs 10.6+/-6.47 mmol x h/L) compared with 70/30.

CONCLUSIONS

In patients with type 2 diabetes mellitus, premeal injection of Mix75/25 resulted in better postprandial glycemic control than did premeal injection of 70/30 in the 4 hours after a standard meal. Mix75/25 is a valuable option for managing postprandial blood glucose in patients with type 2 diabetes mellitus who require insulin.