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1.
J Mater Chem B ; 6(4): 550-555, 2018 Jan 28.
Article in English | MEDLINE | ID: mdl-32254483

ABSTRACT

The short shelf-life of water-soluble quantum dots (QDs) due to colloidal instability represents a major drawback to their exploitation. This work examines the colloidal stability of PbS nanoparticles capped with dihydrolipoic acid-polyethylene glycol (DHLA-PEG) ligands terminated with functional groups such as -NH2, -COOH, OMe and -N3. and their application for in vivo imaging. We prove a mechanism of colloidal instability and develop a strategy to produce for the first time stable PEG-capped PbS quantum dots with high quantum yield and optical emission in the first and the second near-infrared (NIR) windows of low absorption of biological tissues. The NIR imaging of in vivo biodistribution is demonstrated at wavelengths >1000 nm, with benefits of reduced tissue absorption and light scattering. The stability, biocompatibility and potential for further QD functionalization open up realistic prospects for non-invasive bioimaging applications.

2.
Neuropsychobiology ; 44(3): 134-8, 2001.
Article in English | MEDLINE | ID: mdl-11586053

ABSTRACT

Sixteen outpatients (mean age +/- SD 50.18 +/- 11.55 years; 11 females and 5 males) affected by major depression without melancholia (DSM-IV) were included in the study. The control group consisted of 11 healthy volunteers (mean age +/- SD 39.90 +/- 13.39 years; 2 females and 9 males). Patients were treated with fluvoxamine (FVX) 100-300 mg daily. Clinical assessment was performed using the Hamilton Rating Scales for Anxiety and Depression (HRS-A; HRS-D) and the Clinical Global Impression Scale (CGI) at basal time (T(0)), after 4 weeks and after 8 weeks (T(8)). Plasma and platelet amino acid levels were determined at T(0) in all the subjects and also at T(8) in depressed patients. A significant clinical improvement was observed in depressed patients according to the HRS-A (p = 0.004), HRS-D (p = 0.008) and CGI (p = 0.002). A negative correlation (r = -0.53, p = 0.049) was found between platelet levels of valine and HRS-D improvement rate. Patients showed significantly higher tyrosine/large neutral amino acids (LNAAs) and lower tryptophan/LNAAs, ratios which could represent an index of good response to a serotonergic drug like FVX.


Subject(s)
Amino Acids/blood , Depressive Disorder, Major/blood , Depressive Disorder, Major/drug therapy , Fluvoxamine/therapeutic use , Selective Serotonin Reuptake Inhibitors/therapeutic use , Adult , Aged , Analysis of Variance , Blood Platelets/metabolism , Female , Humans , Male , Middle Aged , Predictive Value of Tests
3.
Neuropsychobiology ; 37(3): 124-9, 1998.
Article in English | MEDLINE | ID: mdl-9597668

ABSTRACT

Plasma and platelet levels of 18 amino acids were measured in 29 outpatients (mean age +/- SD 47.41 +/- 10.85 years; 14 F, 15 M) affected by major depression (DSM IV) and in 28 healthy volunteers (mean age 42.46 +/- 14.19 years; 12 F, 16 M). Plasma and platelet levels of amino acids tended to be higher in depressed patients than in healthy controls. In particular, glutamate, taurine and lysine plasma levels and aspartate, serine and lysine platelet levels were significantly higher. Tryptophan/large neutral amino acids ratio (trp/LNAAs) was significantly lower in depressed patients. Fluvoxamine treatment did not influence plasma and platelet levels of amino acids or trp/LNAAs ratio.


Subject(s)
Amino Acids/blood , Antidepressive Agents, Second-Generation/therapeutic use , Blood Platelets/drug effects , Depressive Disorder, Major/drug therapy , Fluvoxamine/therapeutic use , Adult , Aged , Antidepressive Agents, Second-Generation/adverse effects , Blood Platelets/metabolism , Depressive Disorder, Major/blood , Depressive Disorder, Major/psychology , Female , Fluvoxamine/adverse effects , Humans , Male , Middle Aged , Reference Values , Tryptophan/blood
4.
Headache ; 35(4): 216-21, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7539781

ABSTRACT

We investigated the platelet and plasma levels of serotonin and its metabolite, 5-hydroxyindoleacetic acid, in patients suffering from episodic tension-type headache and migraine with and without aura, during a headache-free period. In female subjects, blood samples were drawn during the follicular, ovulatory, and late luteal phases of the menstrual cycle. In tension headache and migraine with aura, the group mean values of serotonin and 5-hydroxyindoleacetic acid in platelets and plasma were significantly increased, but migraine without aura patients' levels were normal. The pattern of menstrual cycle-related fluctuations in platelet serotonin levels were similar in female patients with tension headache and in controls, with a maximum value in the follicular phase. In both migraine groups, in contrast, the peak occurred in the ovulatory phase. The results are discussed in view of whether these aberrations in peripheral markers of the metabolism and menstrual cycle-related rhythmicity of serotonin may reflect similar alterations in the central nervous system.


Subject(s)
Menstrual Cycle , Migraine Disorders/metabolism , Periodicity , Serotonin/metabolism , Tension-Type Headache/metabolism , Adolescent , Adult , Blood Platelets/chemistry , Child , Female , Humans , Hydroxyindoleacetic Acid/blood , Male , Middle Aged , Migraine Disorders/classification , Migraine Disorders/physiopathology , Platelet Count , Serotonin/blood , Tension-Type Headache/physiopathology
5.
Cephalalgia ; 15(2): 132-5, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7641248

ABSTRACT

We evaluated plasma and platelet glutamate and glutamine levels in migraine with and without aura during headache-free periods and compared the results with those of normal controls. The plasma and platelet levels of glutamine in migraine with and without aura were normal. Migraine without aura patients had higher glutamate levels in plasma, and normal platelet levels. In migraine with aura patients, glutamate levels were high in platelets, but not in plasma. This suggests different profiles of excitatory amino acid metabolism in migraine with and without aura.


Subject(s)
Blood Platelets/metabolism , Glutamic Acid/blood , Glutamine/blood , Migraine Disorders/blood , Adolescent , Adult , Analysis of Variance , Case-Control Studies , Female , Humans , Male , Middle Aged , Reference Values
6.
Cephalalgia ; 14(5): 352-6, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7828194

ABSTRACT

We studied whole blood platelet aggregation induced by collagen, platelet activating factor (PAF) and measured basal platelet L-arginine (L-arg) levels, as an indirect index of the nitric oxide (NO) pathway in migraine. Migraine, both with and without aura groups, showed a reduced aggregation to collagen, but not to PAF, compared with control subjects. Platelet L-arg levels were significantly increased in migraine with aura sufferers, whereas the plasma levels were in the same range in migraineurs and controls. Platelet hyperesponsiveness to collagen stimulation in migraine may be linked to an increased availability of the amino acid precursor and an abnormal NO synthesis.


Subject(s)
Arginine/biosynthesis , Blood Platelets/metabolism , Migraine Disorders/blood , Nitric Oxide/metabolism , Platelet Aggregation , Adolescent , Adult , Arginine/blood , Blood Platelets/drug effects , Collagen/pharmacology , Female , Humans , Male , Matched-Pair Analysis , Middle Aged , Platelet Activating Factor/pharmacology , Platelet Aggregation/drug effects
7.
Am J Psychiatry ; 150(11): 1731-3, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8214185

ABSTRACT

Plasma and platelet levels of excitatory amino acids were measured in 38 psychiatric out-patients and in 19 comparison subjects; the patients had DSM-III-R diagnoses of organic mental disorders (N = 3), mood disorders (N = 15), schizophrenia (N = 13), and anxiety disorders (N = 7). The glutamate plasma levels were significantly higher in the patients with mood disorders than in the comparison group.


Subject(s)
Amino Acids/blood , Blood Platelets/chemistry , Mental Disorders/blood , Ambulatory Care , Amino Acids/metabolism , Anxiety Disorders/blood , Blood-Brain Barrier , Depressive Disorder/blood , Depressive Disorder/metabolism , Glutamates/blood , Humans , Neurocognitive Disorders/blood , Schizophrenia/blood
9.
J Neurol Neurosurg Psychiatry ; 55(4): 308-9, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1583516

ABSTRACT

Platelet tyrosine and catecholamine (CA) content was measured in cluster headache sufferers during the different phases of the illness. Compared with controls, cluster headache sufferers had lower platelet levels of norepinephrine (NE) and epinephrine (E) in all phases of the syndrome. Tyrosine levels were increased significantly during the cluster headache attack. We suggest that these results provide biochemical evidence of sympathetic nervous system (SNS) hypofunction in cluster headache.


Subject(s)
Blood Platelets/metabolism , Cluster Headache/blood , Epinephrine/blood , Norepinephrine/blood , Adult , Female , Humans , Male , Middle Aged , Tyrosine/blood
10.
Cephalalgia ; 11(4): 197-200, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1683816

ABSTRACT

Platelet levels of glutamic and aspartic acid and glycine were measured in patients with migraine with aura, migraine without aura, tension headache and cluster headache. High levels of these amino acids were found in patients with migraine with aura compared to normal subjects and other headache groups. During headache, glutamate levels further increased in migraine with aura patients. These findings may have relevance to the neurological symptoms of migraine with aura.


Subject(s)
Aspartic Acid/blood , Blood Platelets/metabolism , Glutamates/blood , Glycine/blood , Headache/blood , Cluster Headache/blood , Glutamic Acid , Humans , Migraine Disorders/blood , Reference Values
11.
Funct Neurol ; 4(1): 79-83, 1989.
Article in English | MEDLINE | ID: mdl-2737498

ABSTRACT

In order to evaluate the role of the sympathetic autonomic nervous system (SANS) in common migraine we measured platelet catecholamine levels in a group of patients and in control subjects after 1 and 30 min of supine rest. Common migraine patients showed, at 1 min of supine rest, higher platelet norepinephrine (NE) content in comparison with the controls. This result may reflect a decreased release of platelet dense bodies in migraineurs. The same patients showed after 30' of supine rest a hardly significant increase of platelet NE levels in contrast to the clearly significant increase found in controls. These findings support the hypothesis of sympathetic hypofunction in migraine.


Subject(s)
Autonomic Nervous System/physiopathology , Blood Platelets/metabolism , Catecholamines/metabolism , Migraine Disorders/physiopathology , Adult , Autonomic Nervous System/metabolism , Dopamine/metabolism , Epinephrine/metabolism , Female , Humans , Migraine Disorders/blood , Norepinephrine/metabolism
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