Wax worm saliva and the enzymes therein are the key to polyethylene degradation by Galleria mellonella.

Plastic degradation by biological systems with re-utilization of the by-products could be a future solution to the global threat of plastic waste accumulation. Here, we report that the saliva of Galleria mellonella larvae (wax worms) is capable of oxidizing and depolymerizing polyethylene (PE), one of the most produced and sturdy polyolefin-derived plastics. This effect is achieved after a few hours' exposure at room temperature under physiological conditions (neutral pH). The wax worm saliva can overcome the bottleneck step in PE biodegradation, namely the initial oxidation step. Within the saliva, we identify two enzymes, belonging to the phenol oxidase family, that can reproduce the same effect. To the best of our knowledge, these enzymes are the first animal enzymes with this capability, opening the way to potential solutions for plastic waste management through bio-recycling/up-cycling.

Biodegradable multi-walled carbon nanotubes trigger anti-tumoral effects.

Carbon nanotubes are of huge biotechnological interest because they can penetrate most biological barriers and, inside cells, can biomimetically interact with the cytoskeletal filaments, triggering anti-proliferative and cytotoxic effects in highly dividing cells. Unfortunately, their intrinsic properties and bio-persistence represent a putative hazard that relapses their application as therapies against cancer. Here we investigate mild oxidation treatments to improve the intracellular enzymatic digestion of MWCNTs, but preserving their morphology, responsible for their intrinsic cytotoxic properties. Cell imaging techniques and confocal Raman spectroscopic signature analysis revealed that cultured macrophages can degrade bundles of oxidized MWCNTs (o-MWCNTs) in a few days. The isolation of nanotubes from these phagocytes 96 hours after exposure confirmed a significant reduction of approximately 30% in the total length of these filaments compared to the control o-MWCNTs extracted from the cell culture medium, or the intracellular pristine MWCNTs. More interestingly, in vivo single intratumoral injections of o-MWCNTs triggered ca. 30% solid melanoma tumour growth-inhibitory effects while displaying significant signs of biodegradation at the tumoral/peri-tumoral tissues a week after the therapy has had the effect. These results support the potential use of o-MWCNTs as antitumoral agents and reveal interesting clues of how to enhance the efficient clearance of in vivo carbon nanotubes.

Association of the 163A/G and 1181G/C osteoprotegerin polymorphism with bone mineral density.

The aim of the study was to investigate the distribution of 163 A/G osteoprotegerin gene promoter and 1181 G/C osteoprotegerin exon 1 polymorphisms in a group of women with different hormonal status and to analyze their relationship with BMD. Osteoprotegerin polymorphisms and BMD were analyzed in 332 women (69 premenopausal and 263 postmenopausal). BMD was quantified at the lumbar spine (L 2-4), femoral neck, and total hip. Genotyping for the presence of different polymorphisms was performed using the Custom Taqman ((R)) SNP Genotyping assays. There were not significant differences in BMD according to 163 A/G genotype. However, significant differences in lumbar spine BMD were found according to 1181 G/C alleles. Thus, women with CC genotype had significant higher BMD at the lumbar spine than those with GC or GG genotype. No differences were found in femoral neck and total hip BMD. In age-adjusted models, the 1181 G/C OPG polymorphism explained 2.2% of BMD variance at the spine, 0.3% at the femoral neck, and 0.9% at the total hip in the whole group. In the subgroup of premenopausal women, the polymorphism was strongly related to spine BMD, and explained 11.5% of the variance, whereas body weight explained 7.9%. The 1181 G/C polymorphism was associated with lumbar spine BMD in Spanish women. Premenopausal women with the CC genotype had a higher BMD.

Blood-soluble Fas levels are increased in type 2 diabetic patients with peripheral vascular disease.

AIM: To investigate the possible utility of plasma sFas (soluble Fas) levels as a marker of peripheral vascular disease (PVD) in type 2 diabetic patients, and the relationship between classical cardiovascular risk factors and sFas levels in these patients. MATERIALS AND METHODS: sFas levels were measured in 57 type 2 diabetic patients with and 60 without PVD matched for age and sex. Diagnosis of PVD was established in presence of at least one of the following criteria: leg or foot amputation of vascular cause, lower-extremity arterial angioplasty or surgical by-pass, or ankle-braquial index (ABI) less than 1 in at least one side of the body. ELISA was used to measure sFas levels. RESULTS: None of the risk factors assessed total cholesterol, HDL cholesterol, triglycerides, CRP, ACE, fibrinogen, Lp(a) and homocysteine was significantly different between both groups of patients. However, patients with PVD had higher plasma sFas levels than the group without PVD (10.25+/-3.7 ng/ml VS. 8.86+/-2.6 ng/ml; p=0.02). Levels of sFas were 1.45 ng/ml (95% CI: 0.32-2.58; p=0.013) higher in PVD patients when adjusting by age, total, HDL and LDL cholesterol, triglycerides, homocysteine, CRP, ACE, arterial hypertension and tobacco smoking. Using multiple logistic regression sFas is a predictor of PVD, although not potent. CONCLUSION: Plasma sFas may be an independent marker of PVD in type 2 diabetes mellitus patients.

Levels of plasma total adrenomedullin are related with two acute phase inflammatory reactants (fibrinogen and sialic acid) but not with markers of endothelial dysfunction in Type 1 diabetes Adrenomedullin and vascular risk factors in Type 1 DM.

Adrenomedullin (AM), an ubiquitous regulatory peptide with different actions, is known to be elevated in different clinical situations, including diabetes mellitus (DM), but its potential role in the pathogenesis of diabetic vascular complications is not clear. In the present study, we examined plasma total AM levels, and their association with different markers of endothelial dysfunction and with other established risk factors for cardiovascular diseases, in patients with Type 1 DM. We studied a total of 155 patients, 117 patients without any kind of vascular complications, 24 patients with retinopathy only, and 14 patients with retinopathy and microalbuminuria but normal renal function. None of them had clinical evidence of atherosclerotic disease. Compared with the control group (64 healthy participants), patients had raised fibrinogen, soluble E-selectin ((s)E-selectin), vascular cellular adhesion molecule (VCAM), angiotensin converting enzyme (ACE), and von Willebrand factor (vWf) (P<.001 in all cases), but plasma total AM, endothelin (ET), sialic acid, and homocysteine were not raised. In the diabetic group, AM levels correlated significantly with sialic acid (r=.16; P<.05), but a more significant correlation was found with fibrinogen (r=.30; P<.001). No correlation was found with the other parameters studied. In summary, plasma total AM levels seem to correlate with inflammatory markers but not with endothelial dysfunction markers in Type 1 diabetic patients without atherosclerotic disease.

Decreased plasma endothelin-1 levels in asymptomatic type I diabetic patients with regional cerebral hypoperfusion assessed by Spect.

The prevalence of stroke is increased in diabetic patients. The vasoconstrictor peptide endothelin-1 (ET-1) has been implicated in the development of cerebral vasospasm after stroke but its role in the physiological regulation of cerebral blood flow (CBF) is not well known. Our aim was to assess the relationship between CBF and plasma ET-1 levels in type I diabetic patients. Regional CBF was assessed semi-quantitatively by 99Tc(m)-hexamethylpropylene-amine-oxime (99Tc(m)-HMPAO) single photon emission computed tomography (SPECT) in 50 cerebral "regions of interest" (ROIs) of 19 type I diabetic patients without clinical evidence of cerebral disease, and 10 healthy control subjects. In both groups, plasma ET-1 levels were measured. Results showed that type I diabetic patients had significantly more hypoperfusion ROIs than control subjects. While up to 68.4% of the type I diabetic patients showed 3 or more hypoperfusion ROIs, only 10% of the control subjects did. Plasma ET-1 levels were lower in the type I diabetes subgroup with 3 or more hypoperfusion ROIs than in the type I diabetes subgroup with less than 3 hypoperfusion ROIs and in the control group. Moreover, an inverse correlation between the number of hypoperfusion ROIs and plasma ET-1 levels (r = 0.47, p = 0.04) was found in the type I diabetes group. It is concluded that plasma ET-1 is decreased in type I diabetic patients with subclinical abnormalities of regional CBF assessed by cerebral SPECT. This fact may reflect a compensatory response to the reduction of the brain perfusion in order to prevent ischemic events in these patients.

Plasma adrenomedullin levels in type 1 diabetes. Relationship with clinical parameters.

OBJECTIVE: To assess the relationship between plasma adrenomedullin (AM) levels and the presence of microvascular complications in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: We measured plasma AM and cAMP levels in 103 type 1 diabetic patients (46 without complications, 24 with retinopathy only, 14 with microalbuminuria but normal kidney function, and 19 with renal insufficiency) and 41 matched healthy control subjects. RESULTS: Patients with renal insufficiency had higher levels of AM and cAMP than all other groups. Patients with only retinopathy showed a trend to have higher levels than patients without complications. There were no differences among all other groups. There was a significant correlation between AM and cAMP in the total diabetic group (rs = 0.36, P < 0.001) but not in the control group. In multiple regression analysis, plasma AM demonstrated significant relationships with creatinine clearance (beta = -0.31, P = 0.004) and duration of the disease (beta = 0.28, P = 0.008). CONCLUSIONS: Plasma AM and cAMP are increased in type 1 diabetic patients with renal insufficiency. Creatinine clearance (CrClc) and duration of the disease are related to plasma AM levels in these patients.

Influence of kidney or heart transplantation on the urinary excretion of epidermal growth factor.

We studied urinary epidermal growth factor (uEGF) in kidney transplant patients with normal and elevated serum creatinine, in cardiac transplant patients with normal serum creatinine, and in patients with chronic renal failure. Patients with chronic renal failure had the lowest uEGF levels. uEGF was reduced in normally functioning kidney transplant patients. If the kidney graft was failing, this reduction was more marked. Cardiac transplant patients had normal uEGF. The type of immunosuppressive therapy did not influence the uEGF excretion. Kidney function and kidney tissue mass appeared to be the most important factors in uEGF excretion.

Lack of effect of octreotide on parathyroid hormone levels and urinary excretion of epidermal growth factor.

To determine whether octreotide may acutely modify calcium homeostasis and/or inhibit the EGF production by the kidney, a subcutaneous injection of octreotide (100 micrograms) was administered to ten healthy volunteers. Blood and urine samples were collected at -30, 0, 60, 90, 120 and 180 minutes. Serum insulin, intact PTH, osteocalcin, total and ionized calcium and urinary EGF and creatinine were measured. There was no modification in serum PTH, osteocalcin and total or ionized calcium. There was no significant modification of urinary EGF, although a trend to decrease was evidenced.

Assessment of the hypothalamic-pituitary-adrenal axis function after corticosteroid therapy for MS relapses.

Doses of corticosteroids usually given for relapses of MS are able to suppress the hypothalamic-pituitary-adrenal (HPA) axis. We evaluated HPA axis function using rapid ACTH stimulation and rapid overnight metyrapone tests, just after cessation of regular oral prednisone therapy for relapses in 14 MS patients. Nine additional patients treated with i.v. boluses of methylprednisolone before beginning conventional oral therapy were also evaluated. Sixteen patients had normal response to both tests and 6 patients had only a discordant response to one test. These data indicate that most patients had normal HPA axis function, which make corticosteroid replacement unnecessary after cessation of therapy for relapses.

[Bone turnover markers in tumor pathology with bone involvement]. / Marcadores del recambio óseo en la patología tumoral con repercusión ósea.

We evaluated the serum osteocalcin and alkaline phosphatase levels and the urinary hydroxyproline excretion in patients with blastic, lithic or mixed metastases, humoral malignant hypercalcemia (HMH) and myeloma. In patients with metastasis of any type osteocalcin did not reach a significant increase although in blastic metastases an increase approaching signification was observed. However, the sensitivities of alkaline phosphatase or hydroxyproline were much higher. In HMH hydroxyproline increased to levels similar to those found in primary hyperparathyroidism. By contrast, although osteocalcin had a significant increase, its values were much lower than in parathyroid disease. The changes in alkaline phosphatase were nonevaluable. In myeloma none of the three markers changed. The major conclusion of the present study is that osteocalcin has little practical usefulness for the investigation of neoplastic patients.

Successful treatment with ketoconazole of Cushing's syndrome in pregnancy.

Patients with Cushing's syndrome rarely become pregnant. This is a high risk situation both for the fetus and the mother, if untreated. We report a patient with Cushing's syndrome due to adrenocortical adenoma who became pregnant and was successfully treated with ketoconazole during the last period of pregnancy.

[Different behavior of bone turnover markers in endocrine (extrinsic) and structural (intrinsic) osteopathies]. / Diferente comportamiento de los marcadores del recambio óseo en las osteopatías endocrinológicas (extrínsecas) y en las estructurales (intrínsecas).

Alkaline phosphatase, osteocalcin and hydroxyproline levels were evaluated in patients with the following conditions: primary hyperparathyroidism, renal dialysis, hyperthyroidism, Cushing's syndrome, long term corticosteroid therapy, Paget's disease, osteoblastic metastases, osteolytic or mixed metastases, and nutritional osteomalacia. In all cases the levels of the three substances were increased, with the following exceptions: a) in endogenous or exogenous hypercortisolism states osteocalcin level was reduced and those of alkaline phosphatase and hydroxyproline were unchanged; and b) in blastic or lytic metastases osteocalcin level was unchanged. In general, alkaline phosphatase and hydroxyproline levels had a higher sensitivity than those of osteocalcin in structural bone disease (Paget's disease, blastic or lytic metastases), whereas the converse was true for endocrine bone disease (the remaining conditions except osteomalacia, which is mixed, both structural and endocrine; in this syndrome, the three substances showed the same sensitivity.

[Pathologic fracture of the sternum in a patient with anorexia nervosa]. / Fractura patológica de esternón en paciente con anorexia nerviosa.

It has been observed that anorexia nervosa (AN) patients present osteoporosis (OP) although the mechanism by which it occurs is not well known. The reduction in calcium intake as well as a decrease in estrogen production which is associated with involutive OP, could be involved. We have found in the literature 16 cases of AN and OP, one of which presented a fracture of the sternum. We now present another case of fracture of the sternum. This implies a high incidence of this type of fracture in OP due to AN which is extremely rare in involutive OP, which suggests that the ethiopathogenic factors of the former are different from those of the latter.

[Effect of active metabolites of vitamin D on manifestations of primary hyperparathyroidism]. / Influencia de los metabolitos activos de la vitamina D en las manifestaciones del hiperparatiroidismo primario.

We have evaluated the serum levels of 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D (1.25-OHD) in 33 patients with primary hyperparathyroidism and normal renal function, relating them with the clinical expression of the disease and other biochemical parameters. The level of 1.25-OHD of the patients was significantly higher than in healthy controls [51 +/- 18 vs 36 +/- 10 pg/ml (122 +/- 43 vs 86 +/- 24 pmol/l), p less than 0.001], although it was higher than the upper limit of the normal range in only 36% of patients. By contrast, the level of 25-OHD was diminished [11.0 +/- 6.3 ng/ml (27.5 +/- 15.7 nmol/l) in the patients and 19.9 +/- 10.5 ng/ml (49.7 +/- 26.2 nmol/l) in the controls, p less than 0.01]. A positive correlation was found between PTH and 1.25-OHD (r = 0.40, p less than 0.05) and a negative one between PTH and 25-OHD (r = -0.40, p less than 0.05). Calcemia was correlated with PTH (r = 0.77, less than p 0.001) but not with 1.25-OHD (partial r = 0.22). There was no correlation between vitamin D metabolites and calciuria, nor between the former and the biochemical indexes of bone remodelling. There were no significant biochemical differences between patients with renal calculi and those without them. It was concluded that PTH level appears as the major determinant factor of 1.25-OHD serum level. The serum level of vitamin D metabolites does not seem to clearly influence calcemia, calciuria, bone remodelling or the development of calculi.

No effect of verapamil on calcium stimulated calcitonin release.

We investigated the effect of infusing 5 mg/h of verapamil on calcitonin release in normal males. After 60 minutes of infusion, ionized calcium and calcitonin levels were unchanged. At 60 minutes we infused 3 mg/kg of body weight of elemental calcium over 10 minutes and we found that calcitonin release was no different from when the subjects were receiving verapamil. These results suggest that, despite blocking calcium channels, acute hypercalcaemia produces normal calcitonin release.