Mast cells decrease efficacy of anti-angiogenic therapy by secreting matrix-degrading granzyme B

Resistance towards VEGF-centered anti-angiogenic therapy still represents a substantial clinical challenge. We report here that mast cells alter the proliferative and organizational state of endothelial cells which reduces the efficacy of anti-angiogenic therapy. Consequently, absence of mast cells sensitizes tumor vessels for anti-angiogenic therapy in different tumor models. Mechanistically, anti-angiogenic therapy only initially reduces tumor vessel proliferation, however, this treatment effect was abrogated over time as a result of mast cell-mediated restimulation of angiogenesis. We show that mast cells secrete increased amounts of granzyme b upon therapy, which mobilizes pro-angiogenic laminin- and vitronectin-bound FGF-1 and GM-CSF from the tumor matrix. In addition, mast cells also diminish efficacy of anti-angiogenic therapy by secretion of FGF-2. These pro-angiogenic factors act beside the targeted VEGFA–VEGFR2-axis and reinduce endothelial cell proliferation and angiogenesis despite the presence of anti-angiogenic therapy. Importantly, inhibition of mast cell degranulation with cromolyn is able to improve efficacy of anti-angiogenic therapy. Thus, concomitant mast cell-targeting might lead to improved efficacy of anti-angiogenic therapy.

Resistance towards VEGF-centered anti-angiogenic therapy is an important clinical challenge. Here, the authors show that mast cells mediate resistance to anti-angiogenetic inhibitors by altering the proliferative and organizational state of endothelial cells through mobilization of FGF-1 and GM-CSF from the tumor matrix and secretion of FGF-2.

Role of Growth arrest-specific gene 6-Mer axis in multiple myeloma

Multiple myeloma is a mostly incurable malignancy characterized by the expansion of a malignant plasma cell (PC) clone in the human bone marrow (BM). Myeloma cells closely interact with the BM stroma, which secretes soluble factors that foster myeloma progression and therapy resistance. Growth arrest-specific gene 6 (Gas6) is produced by BM-derived stroma cells and can promote malignancy. However, the role of Gas6 and its receptors Axl, Tyro3 and Mer (TAM receptors) in myeloma is unknown. We therefore investigated their expression in myeloma cell lines and in the BM of myeloma patients and healthy donors. Gas6 showed increased expression in sorted BMPCs of myeloma patients compared with healthy controls. The fraction of Mer(+) BMPCs was increased in myeloma patients in comparison with healthy controls whereas Axl and Tyro3 were not expressed by BMPCs in the majority of patients. Downregulation of Gas6 and Mer inhibited the proliferation of different myeloma cell lines, whereas knocking down Axl or Tyro3 had no effect. Inhibition of the Gas6 receptor Mer or therapeutic targeting of Gas6 by warfarin reduced myeloma burden and improved survival in a systemic model of myeloma. Thus, the Gas6-Mer axis represents a novel candidate for therapeutic intervention in this incurable malignancy.

Recent Results in the Crystal Growth of GaN at High N2 Pressure

We present recent results on bulk GaN crystallization. The best quality GaN crystals grown from the solution at high N2 pressure without an intentional seeding are single crystalline platelets of stable morphology reaching dimensions up to 10 mm. The fastest growth direction for such crystals is [1 0 0], perpendicular to the GaN c-axis. The maximum stable growth rate perpendicular to crystal c-axis is determined from the experiment and used for an estimate of the effective supersaturation for the {10 0} face assuming two dimensional layer growth. The heat of GaN disssolution, determined from experimental solubility data, is used for the estimation of the edge energy of 2-D nuclei on the growing {10 0} face. Bulk crystal growth seeded by a single hexagonal needle with well developed {10 0} faces is also reported. The crystallization mechanisms and morphological stability in seeded growth of GaN are discussed on the basis of experimental results. The physical properties of the GaN crystals and homoepitaxial layers grown on them are briefly reviewed.

Cement mantle stress under retroversion torque at heel-strike

The paper presents a theory of fixation failure and loosening in cemented total hip prostheses and proceeds to investigate this using an experimentally validated finite element model and two prosthesis types, namely the Charnley and the C-Stem. The study investigates the effects of retroversion torque occurring at heel-strike in combination with a loss of proximal cement/bone support and distal implant/cement support with a good distal cement/bone interface. A 3D finite element model was validated by comparison of femoral surface strains with those measured in an in vitro experimental simulation using an implanted Sawbone femur loaded in the heel-strike position and including a simplified representation of muscle forces. Results showed that the heel-strike position applies a high retroversion torque to the femoral stem that when combined with proximal debonding of the cement/bone interface and distal debonding of the implant/cement interface increases the strain transfer to the cement that may ultimately lead to the breakdown of the cement mantle leading on to osteolysis and loosening of the prostheses. Experimental fatigue testing of the implanted Charnley stem in a Sawbone femur produced cracks within the cement mantle that were located in positions of maximum stress supporting the finite element analysis results and theory of failure.

Potential biomarkers of an exaggerated response to endotoxemia

Serial plasma protein analysis was used to study the acute plasma proteome response to endotoxemia (presence of toxic bacterial products called endotoxins in the blood stream). Plasma samples from healthy volunteers before and multiple time points up to 24 h following administration of low-dose endotoxin were evaluated. Plasma protein profiles were obtained by rapid extraction of whole plasma followed by analysis with matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The profiles were unique to each individual and stable over the time of the experiment. Administration of low-dose endotoxin caused profound change in six of 18 individuals. At 8 h many proteins showed quantitative oxidation, in addition to the appearance of new components and disappearance of common baseline components. An exceptionally intense new component at 4154 mass units was identified as the activation peptide of C1 esterase inhibitor. While recovery of baseline protein structure was nearly complete by 24 h, serum amyloid A, an acute-phase reactant, was still increasing and minor profile changes persisted. Clinical features did not distinguish these extreme responders from others, suggesting that plasma proteome changes offered unique insights into and potential biomarkers of subclinical events following endotoxin exposure.

Plasma adiponectin and serum advanced glycated end-products increase and plasma lipid concentrations decrease with increasing duration of type 2 diabetes

OBJECTIVE

To prospectively follow the concentrations of plasma adiponectin (p-adiponectin) and serum advanced glycation end-products (s-AGE) in relation to plasma lipids and retinopathy over 3 years in type 2 diabetic patients.

DESIGN AND METHODS

P-adiponectin, s-AGE, plasma lipids and diabetic retinopathy were prospectively evaluated in 61 type 2 diabetic patients at baseline and at follow up 3 years later.

RESULTS

Mean p-adiponectin (from 8.84+/-5.14 to 11.05+/-6.16 microg/ml; P=0.006) and s-AGE (from 637+/-242 to 781+/-173 ng/ml; P<0.0001) concentrations had increased at follow up. In addition, HbA1c (7.7+/-1.7 to 7.4+/-1.4%; P=0.0045) and fasting C-peptide (1.00+/-0.38 to 0.81+/-0.35 nM; P=0.019) had decreased and all lipid variables had significantly improved at follow up. P-adiponectin correlated inversely with fasting C-peptide (r(s)=-0.273; P=0.045) and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (r(s)=-0.362; P=0.011), and directly with plasma HDL cholesterol (r(s)=0.381; P=0.005) at follow up. Analysis of variance with adiponectin and s-AGE as dependent variables and fasting C-peptide, plasma HDL and plasma LDL cholesterol as covariates demonstrated that the increase in s-AGE was independent (P=0.001) and the increase in p-adiponectin dependent on covariate changes (P=0.862). There was a slight correlation between s-AGE at baseline versus the degree of retinopathy at follow up (r(s)=0.281; P=0.0499).

CONCLUSION

Both p-adiponectin and s-AGE increased during the 3 years. The increase in p-adiponectin was explained by improvements in insulin sensitivity and dyslipidaemia, whereas the increase in s-AGE was independent of changes in metabolic covariates. s-AGE increase when the duration of type 2 diabetes increases.

Cardiovascular autonomic neuropathy associated with carotid atherosclerosis in Type 2 diabetic patients

AIMS

To clarify if cardiovascular autonomic neuropathy is associated with carotid artery atherosclerotic plaques in Type 2 diabetic patients.

METHODS

Cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients 5-6 years after diagnosis of diabetes.

RESULTS

Cardiovascular autonomic neuropathy [abnormal age corrected expiration/inspiration (E/I) ratio or acceleration index (AI)] was found in 13/61 (21%) patients. Patients with cardiovascular autonomic neuropathy showed increased degree of stenosis in the common carotid artery (24.6 +/- 13.2% vs. 14.7 +/- 9.2%; P = 0.014) and a tendency towards a higher plaque score (4.0 +/- 1.7 vs. 3.2 +/- 1.6; P = 0.064). Controlled for age, AI correlated inversely with degree of stenosis (r = -0.39; P = 0.005), plaque score (r = -0.39; P = 0.005), and mean (r = -0.33; P = 0.018) and maximum (r = -0.39; P = 0.004) intima-media thickness in the common carotid artery. In contrast, E/I ratio correlated only slightly with mean intima-media thickness in the common carotid artery (r = -0.28; P = 0.049).

CONCLUSIONS

Cardiovascular autonomic neuropathy was associated with carotid atherosclerosis in Type 2 diabetic patients. Abnormal E/I ratios reflect efferent structural damage to parasympathetic nerves whereas abnormal AI reflects afferent autonomic dysfunction possibly due to impaired baroreceptor sensitivity secondary to carotid atherosclerosis.

Nurses gain more time with patients

Clinical pathways that incorporate charting by exception eliminate repetitive documentation and give nurses more time to educate and care for patients. In this case, nurses report a gain of 15 minutes per patient each day.

Detection of autonomic sympathetic dysfunction in diabetic patients. A study using laser Doppler imaging

OBJECTIVE

To study signs of the disturbed reflex autonomic sympathetic nerve function in type 1 and type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

Measurements were made on 15 type 1 (duration 13-32 years) and on 50 recently diagnosed type 2 diabetic patients (duration 3-4 years). The vasoconstrictor responses in the distal phalanx of the middle finger (locally heated to 40 degrees C) to the cooling of the contralateral arm were measured using Laser Doppler Imaging (LDI). A vasoconstriction index (VAC) was calculated taking age into account and was compared with reference values obtained in 80 control subjects. The diabetic patients were also studied with deep-breathing tests (i.e., the heart-rate variation expressed as the expiration-to-inspiration [E/I] ratio, a test of parasympathetic nerve function).

RESULTS

The vasoconstrictor responses to indirect cooling (VAC) were significantly reduced in the fingers of the diabetic patients, both type 2 (0.77 +/- 0.02 V; P < 0.01) and type 1 (0.83 +/- 0.04 V; P < 0.001), compared with the healthy control subjects (0.65 +/- 0.01); the age-corrected VAC (VACz) was slightly more impaired in type 1 than in type 2 diabetic patients. The frequency of an abnormal VACz corresponded well to the frequency of an abnormal E/I ratio in type 1 diabetic patients (approximately 50%), whereas the frequency of an abnormal VACz was significantly higher than an abnormal E/I ratio among type 2 diabetic patients (11/50 vs. 4/50; P < 0.05).

CONCLUSIONS

Both type 1 and type 2 diabetic patients have impaired cutaneous blood flow regulation. The VAC index seems to be a promising tool for detection of subclinical changes in autonomic sympathetic function.

Gender, autoantibodies, and obesity in newly diagnosed diabetic patients aged 40-75 years

OBJECTIVE

To evaluate the frequency of autoimmune markers (islet cell antibodies (ICA] and glutamic acid decarboxylase antibodies [GADA]) and clinical features in newly diagnosed people with diabetes aged 40-75 years.

RESEARCH DESIGN AND METHODS

Two hundred fifty-nine consecutive patients (aged 40-75 years) with newly suspected diabetes diagnosed during a 2-year period were studied. The diagnosis of newly discovered diabetes was confirmed in 203 patients. Gender, BMI, HbA1c, fasting C-peptide, ICA, and GADA were evaluated. The frequency of obesity was estimated using two different sets of criteria: 1) National Diabetes Data Group (NDDG) criteria, and 2) criteria based on a Swedish reference population.

RESULTS

The annual incidence of diabetes was 106 per 100,000 people. The incidence of diabetes in those patients who were 40-54 years old was significantly higher in men than in women (odds ratio: 2.16; P = 0.001). ICA were detected in 16 of 203 patients (8%), whereas 17 of 203 patients (8%) were GADA+; 10 of 203 (5%) patients were positive for both ICA and GADA. Among the 203 diabetic patients, 19 (9.4%) were classified as having IDDM, giving an IDDM incidence of 10 per 100,000 people aged 40-75 years. The frequency of obesity in NIDDM was high but varied with its definition; the frequency of obesity was highest (P < 0.001) when NDDG criteria, and not Swedish reference values, were used (57 of 75 [76%] vs. 40 of 75 [53%] for women and 66 of 109 [61%] vs. 45 of 109 [41%] for men).

CONCLUSIONS

A striking male preponderance was found among incident cases of diabetes in people aged 40-54 years. Autoimmune markers were detected in 10% of incident cases of diabetes in people aged 40-75 years. Using a conservative estimation, as many as 10 of 100,000 middle-aged and elderly subjects developed IDDM. The frequency of obesity in NIDDM was high but this was also the case in the reference population.

CD45-mediated signals can trigger shedding of lymphocyte L-selectin

The adhesion molecule L-selectin is proteolytically cleaved from the surface of lymphocytes and neutrophils within minutes after stimulation by phorbol ester or calcium ionophores. In contrast to neutrophils, soluble factors have not been shown to induce down-regulation of L-selectin on lymphocytes. We therefore examined whether signals generated by interaction with cell surface receptors could deliver physiological stimuli inducing this regulatory mechanism. While cross-linking of several adhesion molecules (CD2, CD44, alpha 4-integrin, LFA-1) by antibody did not result in a significant reduction of the expression of L-selectin, antibodies against CD45 and Thy-1.2, both involved in the regulation of lymphocyte activation, induced loss of cell surface L-selectin within minutes, even at 4 degrees C, by shedding into the supernatant. Cross-linking of these molecules was shown to be essential, but Fc interactions or adherent cells were not required. A similar response, albeit less effective, was found after cross-linking of CD3. Interestingly, initiation of shedding only occurred in the presence of cell-cell contact, pointing to a second, as yet unknown, signal required. Loss of L-selectin induced by CD45 cross-linking is followed by a rapid re-expression of the molecule upon incubation at 37 degrees C. This reaction is also dependent on specific triggering signals as rapid re-expression was not observed after removal of L-selectin by trypsin. The data indicate that the protein phosphatase CD45 as well as the TCR complex itself in combination with a further, as yet unknown, cell-cell contact-dependent stimulus have a regulatory role in the dynamic control of L-selectin expression in lymphocytes.

Therapeutic effects of antibodies against adhesion molecules in murine collagen type II-induced arthritis

Adhesion molecules play important roles in immune reactions and inflammatory processes and may constitute attractive targets for immunomodulatory approaches. In this study, blocking mAbs against a series of adhesion molecules were tested for their therapeutic effect on developing arthritis in a mouse model. MAbs were given for a period of 4 weeks at the time of exspected incidence of visible disease symptoms, i.e. 4 weeks after priming with collagen type II. A significant reduction of incidence down to values of 13% and 29% of the controls was obtained with mAbs against CD44 and alpha 4-integrin, respectively, during an observation time of 13 weeks. MAbs against CD4 and LFA-1 resulted only in weaker, non-significant effects or a delay in the incidence. MAbs against other molecules including L-selectin, ICAM-1 or VCAM-1 were not effective. The development of antibodies against collagen type II, collagen type I, proteoglycans and the immunogen, bovine collagen type II was affected by mAb treatment to a different extent. In this case, the anti CD4 mAb was the most effective, followed by the anti alpha 4-antibodies in most cases, whereas anti CD44 showed less clear effects on the development of humoral responses. In a skin delayed type hypersensitivity model analyzed for comparison, mAbs against LFA-1/ICAM-1 and alpha 4-integrin showed the largest effects on ear swelling. These data show that mAbs against several adhesion molecules are able to block selectively distinct aspects of immune reactions, and that CD44 and alpha 4-integrins could be promising targets for an immunotherapy of rheumatoid arthritis with receptor-interfering agents.

Postprandial increase in serum creatinine in renal transplant recipients

Daily variation in serum creatinine and the effect of a protein load was studied in 18 patients with renal transplants and in 10 healthy controls. Serum creatinine was analyzed both with a standard Jaffé method and with a specific HPLC technique. Following a protein meal, a 30% increase in serum creatinine levels was noted in both groups, but the rise in absolute terms was more prominent among the transplanted patients. Urinary excretion of creatinine did not increase in the transplanted group, indicating a reduced ability to deal with the surplus creatinine in the protein meal. It is concluded that serum creatinine levels are diet-dependent and that this variation is more pronounced when renal function is reduced. Standardized blood sampling is important when following serum creatinine in renal transplant recipients from one day to the next.

Peritonitis in geriatric inpatients

Of 212 cases of peritonitis found in a retrospective study of geriatric inpatients, the most common causes were mesenteric infarction, malignancy, intestinal obstruction, perforated peptic ulcer, cholecystitis, diverticulitis and perforation of the urinary bladder. The diagnostic accuracy was 47%. Abdominal pain had been observed in only 55% of the cases, and guarding and/or abdominal rigidity in only 34%. Other findings such as tachycardia and fever were more common, but the specificities of these signs were low.

Ulcer disease among geriatric inpatients with positive faecal occult blood test and/or iron deficiency anaemia. A prospective study

The purpose of this study was to investigate the prevalence and type of lesions in the upper gastrointestinal tract and to identify characteristics associated with ulcer disease among geriatric inpatients with positive faecal occult blood test and/or iron deficiency anaemia. Two thousand five hundred and four patients aged 60-98 (mean, 82) years admitted to a geriatric clinic for rehabilitation were screened by faecal occult blood test, for B-haemoglobin, and, in a case of anaemia, analyses of serum levels of mean corpuscular volume, mean corpuscular haemoglobin concentration, iron, and total iron-binding capacity. One hundred and seventy patients were included in the study. A high prevalence of ulcer disease (22%) was found. Significantly higher proportions of non-steroidal anti-inflammatory drugs and steroid users and of patients with rheumatoid arthritis and osteoarthrosis were found among ulcer patients than among patients without ulcerative upper gastrointestinal lesions. The clinical picture of ulcer disease differed from the classic presentation: abdominal pain occurred in only 7 of 38 patients (18%), whereas appetite and weight loss and nausea/vomiting were common. It is important to be aware of the high prevalence and the clinical picture of ulcer disease among geriatric inpatients with iron deficiency anaemia and/or occult gastrointestinal bleeding.

Peptic ulcer in geriatric long-term care medicine

This study was based upon deceased patients in a geriatric university hospital with a high autopsy rate (81%). Of 6200 autopsied patients, 333 (5.4%) had had an active peptic ulcer; agonal and other acute erosions were not included. 257 cases were selected for the study (average age 83.8 yr). The diagnostic accuracy, and the symptoms of peptic ulcer in stationary, elderly, chronically ill patients were studied retrospectively. Only 16% of cases with duodenal ulcer and 29% with gastric ulcer had been correctly diagnosed antemortem. The clinical features of ulcer disease in the elderly may often differ from the standard presentation in younger people. Prior to death, appetite and weight loss, nausea/vomiting, anaemia and positive occult blood test had been more common among patients with ulcer, than abdominal pain and heartburn. The predictive values of single symptoms and of combined findings were low (range 2-21%), thus supporting observations from clinical practice that diagnosis is difficult in geriatric medicine. Prospective studies of ulcer disease in living elderly are needed.

Symptoms of myocardial infarction in old age: clinical case, retrospective and prospective studies

In a clinical case study (n = 71), a retrospective study (n = 96), and a prospective study (n = 60, 10 cases and 50 controls)--all of a duration of three years--prevalence and kind of symptoms of myocardial infarction in geriatric long-term care patients were studied. The findings suggest a low diagnostic accuracy of acute myocardial infarction in the elderly. The clinical features seem to be different compared to those of younger patients. Intense dyspnoea, syncope and weakness are more common than chest pain.