Soluble markers for the assessment of biological activity with PTK787/ZK 222584 (PTK/ZK), a vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor in patients with advanced colorectal cancer from two phase I trials

BACKGROUND

Plasma and serum biomarkers of angiogenesis and activated endothelial cells were evaluated to assess biological activity of PTK787/ZK 222584 (PTK/ZK), a novel oral angiogenesis inhibitor targeting all known vascular endothelial growth factor (VEGF) receptor tyrosine kinases.

PATIENTS AND METHODS

Patients with colorectal cancer (CRC) (n=63) were enrolled into two phase I/II dose escalation trials of PTK/ZK in 28-day cycles until discontinuation. Patients with stable disease for > or =2 months were categorized as 'non-progressors'. Plasma markers of angiogenesis, VEGF-A and basic fibroblast growth factor (bFGF), and the serum markers of activated endothelial cells, sTIE-2 and sE-Selectin, were assessed at baseline, and pre-dose on days 1, 8, 15, 22 and 28 of every cycle, with additional assessments 10 h post-dose on days 1 and 15. The percentage change from baseline was subsequently correlated with AUC and C(max) of PTK/ZK on day 1, cycle 1 and clinical outcome.

RESULTS

A dose-dependent increase in plasma VEGF-A and bFGF was observed in the first cycle of PTK/ZK treatment. The correlation of change in plasma VEGF-A with AUC and C(max) was characterized by an E(max) model, suggesting that a change of > or =150% from baseline VEGF-A correlated with non-progressive disease. Change from baseline plasma VEGF-A within the first cycle of treatment was significantly correlated with clinical outcome by logistic regression analysis (P=0.027).

CONCLUSIONS

In patients with CRC treated with PTK/ZK, changes in plasma VEGF-A and bFGF demonstrate biological activity of PTK/ZK, may help to establish optimal dose and correlate with outcome.

Age and muscle-type modulated role of intramyocellular lipids in the progression of insulin resistance in nondiabetic Zucker rats

The effect of muscle fiber type and maturation on intramyocellular lipid (IMCL) content and its relationship to insulin resistance was investigated. Intramyocellular lipid content in slow-twitch (soleus) and fast-twitch (tibialis anterior, TA) muscles of fa/fa (Zucker fatty rat, ZFR) and age-matched lean (Zucker lean rat, ZLR) Zucker rats were repeatedly measured over 3 months. Intramyocellular lipid levels in both the soleus and the TA were significantly higher in the ZFR relative to the ZLR. For the ZFR, IMCL TA increased by approximately 2-fold from 5.3 to 8.4 weeks of age. No subsequent accumulation of IMCL TA occurred in ZFR from 8.4 up to 13.1 weeks of age. For ZLR, IMCL TA contents steadily decreased from 6.6 to 13.1 weeks of age (-77%, P<.05). In contrast, IMCL levels in the soleus were not significantly altered in either rat strain over the course of the study. Maximum impairment in whole-body insulin sensitivity in ZFR was observed at 9-weeks of age, concomitant with peak IMCL TA accumulation. Insulin-stimulated 2-deoxy-D-glucose (2DG) transport in the TA muscle of 10.2- and 14.1-week-old ZFR was significantly impaired relative to age-matched ZLR. Insulin-stimulated glucose uptake in the soleus of ZFR and ZLR decreased (P<.05) as the animals matured (ZFR, -49%; ZLR, -69%). Overall, these results support the hypothesis that fast-twitch glycolytic muscles play a major role during the onset of insulin resistance. In addition, proper timing may govern the success of a pharmacological studies aimed at measuring the impact of insulin-sensitizing drugs on IMCL.

Relationship between visceral adiposity and intramyocellular lipid content in two rat models of insulin resistance

High visceral adiposity and intramyocellular lipid levels (IMCL) are both associated with the development of type 2 diabetes. The relationship between visceral adiposity and IMCL levels was explored in diet- and glucocorticoid-induced models of insulin resistance. In the diet-induced model, lean and fa/fa Zucker rats were fed either normal or high-fat (HF) chow over 4 wk. Fat distribution, IMCL content in the tibialis anterior (TA) muscle (IMCL(TA)), and whole body insulin resistance were measured before and after the 4-wk period. The HF diet-induced increase in IMCL(TA) was strongly correlated with visceral fat accumulation and greater glucose intolerance in both groups. The increase in IMCL(TA) to visceral fat accumulation was threefold greater for fa/fa rats. In the glucocorticoid-induced model, insulin sensitivity was impaired with dexamethasone. In vivo adiposity and IMCL(TA) content measurements were combined with ex vivo analysis of plasma and muscle tissue. Dexamethasone treatment had minimal effects on visceral fat accumulation while increasing IMCL(TA) levels approximately 30% (P < 0.05) compared with controls. Dexamethasone increased plasma glucose by twofold and increased the saturated fatty acid content of plasma lipids [fatty acid (CH2)n/omegaCH3 ratio +15%, P < 0.05]. The lipid composition of the TA muscle was unchanged by dexamethasone treatment, indicating that the relative increase in IMCL(TA) observed in vivo resulted from a decrease in lipid oxidation. Visceral adiposity may influence IMCL accumulation in the context of dietary manipulations; however, a "causal" relationship still remains to be determined. Dexamethasone-induced insulin resistance likely operates under a different mechanism, i.e., independently of visceral adiposity.

[Eleven cases of leptospirosis: clinical and microbiological features]

OBJECTIVE

The authors had for aim, to describe clinical and biological features of 11 cases of leptospirosis observed in Lorraine between 1996 and 2002, and to assess the interest of diagnostic methods.

PATIENTS AND METHODS

A retrospective study was performed. The inclusion criteria was positive serological test for Leptospira.

RESULTS

The contamination was mainly linked to water sports, during the summer holidays. The main symptom was fever, associated with moderate increase of aminotransferase serum level. Leptospira icterohaemorragiae was the most frequently identified serogroup. One 17-year-old male patient died after infection during water sports practice.

CONCLUSION

Preventive measures should be considered for people exposed to Leptospira when practicing water sports.

Magnetic resonance imaging in drug discovery: lessons from disease areas

Imaging technologies are presently receiving considerable attention in the pharmaceutical area owing to their potential to accelerate the drug discovery and development process. One of the principal imaging modalities is magnetic resonance imaging (MRI). The multiparametric nature of MRI enables anatomical, functional and even molecular information to be obtained non-invasively from intact organisms at high spatial resolution, thereby enabling a comprehensive characterization of a disease state and the corresponding drug intervention. The non-invasiveness of MRI strengthens the link between pre-clinical and clinical drug studies, making the technique attractive for pharmaceutical research.

Effects of depletion exercise and light training on muscle glycogen supercompensation in men

Supercompensated muscle glycogen can be achieved by using several carbohydrate (CHO)-loading protocols. This study compared the effectiveness of two "modified" CHO-loading protocols. Additionally, we determined the effect of light cycle training on muscle glycogen. Subjects completed a depletion (D, n = 15) or nondepletion (ND, n = 10) CHO-loading protocol. After a 2-day adaptation period in a metabolic ward, the D group performed a 120-min cycle exercise at 65% peak oxygen uptake (VO2 peak) followed by 1-min sprints at 120% VO2 peak to exhaustion. The ND group performed only 20-min cycle exercise at 65% VO2 peak. For the next 6 days, both groups ate the same high-CHO diets and performed 20-min daily cycle exercise at 65% VO2 peak followed by a CHO beverage (105 g of CHO). Muscle glycogen concentrations of the vastus lateralis were measured daily with 13C magnetic resonance spectroscopy. On the morning of day 5, muscle glycogen concentrations had increased 1.45 (D) and 1.24 (ND) times baseline (P < 0.001) but did not differ significantly between groups. However, on day 7, muscle glycogen of the D group was significantly greater (p < 0.01) than that of the ND group (130 +/- 7 vs. 104 +/- 5 mmol/l). Daily cycle exercise decreased muscle glycogen by 10 +/- 2 (D) and 14 +/- 5 mmol/l (ND), but muscle glycogen was equal to or greater than preexercise values 24 h later. In conclusion, a CHO-loading protocol that begins with a glycogen-depleting exercise results in significantly greater muscle glycogen that persists longer than a CHO-loading protocol using only an exercise taper. Daily exercise at 65% VO2 peak for 20 min can be performed throughout the CHO-loading protocol without negatively affecting muscle glycogen supercompensation.

In vivo qualitative assessments of articular cartilage in the rabbit knee with high-resolution MRI at 3 T

Proteoglycan (PG) loss and disruption of the collagen framework in cartilage are early events associated with osteoarthritis (OA). The feasibility of in vivo high-resolution MRI assessments probing both macromolecules was explored in articular cartilage of the rabbit knee. One-millimeter thick coronal images were obtained at 3 T with a 97 x 97 microm(2) pixel size. A 22% decrease in the magnetization transfer (MT) exchange rate along with an approximately 2-fold greater Gd(DTPA)(2-)-induced decrease in T(1) relaxation time were measured in response to papain injection 1 day prior to the MRI session, indicative of an alteration of collagen integrity and PG depletion, respectively. A two-point method was tested as an alternative to the more time-consuming multipoint method typically used to measure T(1) changes. Kinetics of Gd(DTPA)(2-) uptake were observed with a 10-min time resolution. The diffusive transport of Gd(DTPA)(2-) was characterized by a T(1) decrease approximately 2-fold faster in papain-treated knees. These data suggest that kinetics of tracer diffusion may be used as an informative marker of PG loss, in addition to the amplitude of T(1) variations. When applied to a relevant OA model, the combination of MT and Gd(DTPA)(2-)-MRI may help in identifying new active compounds during efficacy studies on cartilage protection.

Qualitative and quantitative in vivo assessment of articular cartilage using magnetic resonance imaging

The molecular organization and biochemical composition that give cartilage the viscoelasticity necessary for load distribution also convey unique magnetic resonance (MR) properties. In that context, MR imaging has the potential to detect cartilage degeneration and regeneration. Magnetization transfer (MT) imaging probes the exchange of magnetization between the bulk water pool and the water pool bound to macromolecules such as collagen and hence MT may be applied for evaluation of collagen integrity. In addition, Gd(DTPA)(2-)-induced T1 changes have been proposed as a surrogate marker of proteoglycan (PG) loss based on the principle that the paramagnetic agent Gd(DTPA)2- penetrates cartilage to an equilibrium concentration inversely proportional to the negative charge density (i.e. the PG concentration). Results obtained in vivo from MT and Gd(DTPA)(2-)-enhanced MRI acquisitions on the goat knee showed early signs of biochemical changes in response to a papain injection. A dose-dependent effect of papain was observed with both approaches over a wide range of PG depletion (i.e. T1 measurement) and collagen damage (i.e. MT measurement) as confirmed with post-mortem biochemistry and histology. Development of MRI protocols for non-invasive assessment of cartilage will facilitate diagnosis and monitoring of treatment efficacy in the clinic.

In vivo assessment of macromolecular content in articular cartilage of the goat knee

Loss of proteoglycans (PGs) from the extracellular matrix of cartilage is an early event of osteoarthritis. The capability of Gd(DTPA)(2-)-enhanced MRI to quantitatively assess PG content was explored in a goat model of cartilage degeneration. Partial to total PG depletion was induced by an intraarticular injection of papain 1 day prior to the MRI session. A close correlation was found between the extent of the PG loss and the Gd(DTPA)(2-)-induced T(1) decrease. Papain-induced PG depletion was confirmed by post-mortem histological and biochemical assessments. A 2-hr delay after Gd(DTPA)(2-) injection was found to be optimal for an accurate quantitation of the cartilage defect. A series of knee flexions were performed post-Gd(DTPA)(2-) injection to facilitate penetration of the contrast agent into cartilage. However, DeltaT(1)'s observed in cartilage of exercised goat knees were not affected by papain or IL1beta pretreatment. Therefore, as long as a preinjection T(1) map was obtained, the Gd(DTPA)(2-)-enhanced MRI technique provided good sensitivity in detecting partial loss of PG in articular cartilage. This was true only when the animal was maintained in a resting state during diffusion of the Gd(DTPA)(2-). This approach is of particular interest for long-term evaluations of cartilage degeneration and regeneration.

13C/31P NMR studies on the role of glucose transport/phosphorylation in human glycogen supercompensation

This study measured muscle glycogen during a 7-day carbohydrate loading protocol. Twenty healthy subjects (12 male, 8 female) performed 1 hr treadmill/toe-raise exercise immediately before a 3-day low carbohydrate (LoCHO) diet (20 % carbohydrate, 60 % fat, 20 % protein). On day 3 they repeated the exercise and began a 4-day high carbohydrate (HiCHO) diet (90 % carbohydrate, 2 % fat, 8 % protein). The order of administration of the diet was reversed in a subpopulation (n = 3). Interleaved natural abundance 13C/ 31P NMR spectra were obtained before and immediately after exercise, and each day during the controlled diets in order to determine concentrations of glycogen (GLY), glucose-6-phosphate (G6P), and muscle pH. Following exercise, muscle GLY and pH were reduced (p < 0.001) while muscle G6P was elevated (p </= 0.01). During the 3-day LoCHO diet, fasting concentrations of G6P were not different from resting levels. During the first 3 days of the HiCHO diet, resting G6P was elevated (p </= 0.05) compared to before the study. By the final day, muscle glycogen was 1.6-fold greater than before the protocol, while G6P had returned to baseline. Daily GLY and G6P were not affected by the order in which the diet was administered. We conclude that increased glucose transport/phosphorylation plays a role in muscle glycogen supercompensation.

First steps of otolith formation of the zebrafish: role of glycogen?

The first steps of otolith formation were studied by electron microscopy in zebrafish embryos at different postfertilization (PF) time intervals. Between 19 and 22 h PF, the otic cavity contains glycogen particles derived by an apocrine process from the apical portions of the epithelial cells of the inner ear. The particles are arranged in parallel arrays, then in pseudocrystalloid structures, and finally in concentric arrays to form dense clusters referred to as "spherules". At 23 h PF, a group of "globules", consisting of modified aggregated "spherules" surrounded by several free "spherules", forms the nascent otolith. At 30 h PF, fused globules form a roughly spherical otolith. Spherules undergoing their process of modification and aggregation, are located in its central part, and constitute the so-called "nucleus". At 50 h PF, the otolith is a flattened hemisphere. It is made up of fused globules surrounded by two concentric layers whose organization is similar to that observed in the otolith of the adult fish. At this stage, calcium may be detected in the otolith except in its nucleus. We suggest that glycogen molecules found in the nascent otolith might allow the insertion of molecules such as glycoproteins (collagens) which are known to fix calcium. As a result, glycogen might play a key role in initiating the formation of otoliths and possibly that of other calcified tissues.

Effect of a self-management program on patients with chronic disease

CONTEXT

For patients with chronic disease, there is growing interest in "self-management" programs that emphasize the patients' central role in managing their illness. A recent randomized clinical trial demonstrated the potential of self-management to improve health status and reduce health care utilization in patients with chronic diseases.

OBJECTIVE

To evaluate outcomes of a chronic disease self-management program in a real-world" setting.

STUDY DESIGN

Before-after cohort study.

PATIENTS AND SETTING

Of the 613 patients from various Kaiser Permanente hospitals and clinics recruited for the study, 489 had complete baseline and follow-up data.

INTERVENTION

The Chronic Disease Self-Management Program is a 7-week, small-group intervention attended by people with different chronic conditions. It is taught largely by peer instructors from a highly structured manual. The program is based on self-efficacy theory and emphasizes problem solving, decision making, and confidence building.

MAIN OUTCOME MEASURES

Health behavior, self-efficacy (confidence in ability to deal with health problems), health status, and health care utilization, assessed at baseline and at 12 months by self-administered questionnaires.

RESULTS

At 1 year, participants in the program experienced statistically significant improvements in health behaviors (exercise, cognitive symptom management, and communication with physicians), self-efficacy, and health status (fatigue, shortness of breath, pain, role function, depression, and health distress) and had fewer visits to the emergency department (ED) (0.4 visits in the 6 months prior to baseline, compared with 0.3 in the 6 months prior to follow-up; P = 0.05). There were slightly fewer outpatient visits to physicians and fewer days in hospital, but the differences were not statistically significant. Results were of about the same magnitude as those observed in a previous randomized, controlled trial. Program costs were estimated to be about $200 per participant.

CONCLUSIONS

We replicated the results of our previous clinical trial of a chronic disease self-management program in a "real-world" setting. One year after exposure to the program, most patients experienced statistically significant improvements in a variety of health outcomes and had fewer ED visits.

Effect of essential hypertension on kidney function as measured in rat by dynamic MRI

In this study, dynamic MRI was applied to investigate the effect of genetic hypertension on the renal clearance of Gd(DTPA). Assuming that the paramagnetic agent was essentially cleared through the kidney by glomerular filtration, a first-order kinetic model was used to estimate a rate constant k(cl) describing the transport from the renal cortex to the inner medulla. Experiments were carried out on 12-15-week-old spontaneously hypertensive rats (young-SHR) and age-matched Wistar-Kyoto rats (young-WKY). An additional group of 22-25-week-old SHR (old-SHR) was investigated to assess the long-term effect of chronic hypertension on kidney function. The glomerular filtration rate as measured by the inulin method correlated well with k(cl) results as measured by MRI. A clearance index 30% lower than young-WKY was observed in young-SHR, reflective of a kidney dysfunction. In old-SHR, k(cl) was only 50% of the young-WKY value. As computed from Gd(DTPA) concentration profiles, this translated into delayed time-to-peak (TTP) values, decreased peak Gd(DTPA) concentrations ([Gd](peak)), and a slow elimination of Gd(DTPA) from the blood pool, renal cortex, and inner medulla (e.g., high t(1/2) values). Finally, using the same MRI approach, the data showed that the acute administration of the calcium antagonist verapamil at an antihypertensive dose was followed by a near normalization of SHR renal function. These results indicate that chronic hypertension remains a major pathogenic factor in the progression of glomerular degeneration, as opposed to a primary glomerular defect independent of systemic pressure.

Quantitative and qualitative assessment of articular cartilage in the goat knee with magnetization transfer imaging

We investigated the role of collagen in the magnetization transfer (MT) effect in contrast to other macromolecules. By means of phantoms made of collagen, chondroitin sulfate (CS) and albumin, MR parameters have been optimized in order to reduce the acquisition time and improve the sensitivity, as well as to minimize the contributions from CS and albumin to the MT induced signal attenuation. The same method was used to study cartilage ex vivo (bovine articular and nasal cartilage plugs) and in vivo (goat knee femoral chondyle). In phantom samples, the MT signal attenuation depended on the collagen concentration while contributions from the other macromolecules were found to be minimal. In average, analysis of MT images revealed a approximately 25%, approximately 35% and approximately 30% signal attenuation in 10% w/v type I collagen gels, cartilage plugs, and cartilage from the weight-bearing areas of the goat knee, respectively. Biochemical data revealed that treatment of cartilage plugs with bacterial collagenase led to collagen depletion and correspondingly to a decrease of the MT response. In contrast, trypsin-induced proteoglycan loss in cartilage plugs did not alter the MT effect. A significant correlation was observed between the collagen content in these plugs and their respective MT ratios and the rate constant k for the exchange process bound versus free water. Finally, data obtained from in vivo MT measurement of the goat knee demonstrated that intra-articular injection of papain might not only cause degradation of proteoglycans but also a change in collagen integrity in a dose-dependent manner. We conclude that in vivo measurement of MT ratios gives quantitative and qualitative information on the collagen status and may be applied for the routine evaluation of normal and abnormal articular cartilage.

Effect of a self-management program on patients with chronic disease

CONTEXT

For patients with chronic disease, there is growing interest in "self-management" programs that emphasize the patients' central role in managing their illness. A recent randomized clinical trial demonstrated the potential of self-management to improve health status and reduce health care utilization in patients with chronic diseases.

OBJECTIVE

To evaluate outcomes of a chronic disease self-management program in a real-world" setting.

STUDY DESIGN

Before-after cohort study.

PATIENTS AND SETTING

Of the 613 patients from various Kaiser Permanente hospitals and clinics recruited for the study, 489 had complete baseline and follow-up data.

INTERVENTION

The Chronic Disease Self-Management Program is a 7-week, small-group intervention attended by people with different chronic conditions. It is taught largely by peer instructors from a highly structured manual. The program is based on self-efficacy theory and emphasizes problem solving, decision making, and confidence building.

MAIN OUTCOME MEASURES

Health behavior, self-efficacy (confidence in ability to deal with health problems), health status, and health care utilization, assessed at baseline and at 12 months by self-administered questionnaires.

RESULTS

At 1 year, participants in the program experienced statistically significant improvements in health behaviors (exercise, cognitive symptom management, and communication with physicians), self-efficacy, and health status (fatigue, shortness of breath, pain, role function, depression, and health distress) and had fewer visits to the emergency department (ED) (0.4 visits in the 6 months prior to baseline, compared with 0.3 in the 6 months prior to follow-up; P = 0.05). There were slightly fewer outpatient visits to physicians and fewer days in hospital, but the differences were not statistically significant. Results were of about the same magnitude as those observed in a previous randomized, controlled trial. Program costs were estimated to be about $200 per participant.

CONCLUSIONS

We replicated the results of our previous clinical trial of a chronic disease self-management program in a "real-world" setting. One year after exposure to the program, most patients experienced statistically significant improvements in a variety of health outcomes and had fewer ED visits.

Effects of pioglitazone on adipose tissue remodeling within the setting of obesity and insulin resistance

Obesity and dysfunctional energy partitioning can lead to the development of insulin resistance and type 2 diabetes. The antidiabetic thiazolidinediones shift the energy balance toward storage, leading to an increase in whole-body adiposity. These studies examine the effects of pioglitazone (Pio) on adipose tissue physiology, accumulation, and distribution in female Zucker (fa/fa) rats. Pio treatment (up to 28 days) decreased the insulin-resistant and hyperlipidemic states and increased food consumption and whole-body adiposity. Magnetic resonance imaging (MRI) analysis and weights of fat pads demonstrated that the increase in adiposity was not only limited to the major fat depots but also to fat deposition throughout the body. Adipocyte sizing profiles, fat pad histology, and DNA content show that Pio treatment increased the number of small adipocytes because of both the appearance of new adipocytes and the shrinkage and/or disappearance of existing mature adipocytes. The remodeling was time dependent, with new small adipocytes appearing in clusters throughout the fat pad, and accompanied by a three- to fourfold increase in citrate synthase and fatty acid synthase activity. The appearance of new fat cells and the increase in fat mass were depot specific, with a rank order of responsiveness of ovarian > retroperitoneal > subcutaneous. This differential depot effect resulted in a redistribution of the fat mass in the abdominal region such that there was an increase in the visceral:subcutaneous ratio, as confirmed by MRI analysis. Although the increased adiposity is paradoxical to an improvement in insulin sensitivity, the quantitative increase of adipose mass should be viewed in context of the qualitative changes in adipose tissue, including the remodeling of adipocytes to a smaller size with higher lipid storage potential. This shift in energy balance is likely to result in lower circulating free fatty acid levels, ultimately improving insulin sensitivity and the metabolic state.