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Biomedical subjects

M T Vázquez

Publications and source records attributed to M T Vázquez.

7 recordsLinked to original sources
PubMed2007

Femoral nerve entrapment: a new insight.

Compression of the femoral nerve in the iliac fossa has been reported as a consequence of several pathologies, but never as a result of muscular compression. Aberrant slips of iliacus, however, have occasionally been reported to cover or split the femoral nerve. This study aimed to assess such variations as potential factors in femoral nerve compression. A large and homogeneous sample of 121 embalmed cadavers (242 specimens) was studied. Statistical comparisons were made using the chi-squared test. Muscular slips from iliacus and psoas, piercing or covering the femoral nerve, were found in 19 specimens (7.9%). No significant differences by sex or side were found. The more frequent variation was piercing of the femoral nerve by a muscular slip (17 specimens, 7.0%). The nerve then entered the thigh as one or more branches. The less frequent variation found was a muscular slip or sheet covering the femoral nerve as it lay on iliacus (2 specimens, 0.8%). Each disposition may be a potential risk for nerve entrapment.

Abdominal Muscles↗
PubMed2004

Synthesis of novel 2,3-dihydro-1,4-dioxino[2,3-g]quinoline derivatives as potential antitumor agents.

New dioxinoquinolines (1-8) have been synthesized and their antiproliferative properties have been tested against several cell lines. The treatment of the 6-acetamido-2,3-dihydro-1,4-benzodioxine (10) with phosphorous oxychloride in the presence of DMF leads to a mixture of linear and angular tricyclic compounds. The key intermediates were modified and cyclized giving the corresponding dioxinoquinolines. In general, these compounds have a moderate citotoxycity.

Aniline Compounds↗
PubMed2000

Immunohistochemical localization of neurocalcin in human sensory neurons and mechanoreceptors.

The localization of neurocalcin in the developing and adult human peripheral nervous system (dorsal root and sympathetic ganglia (DRG, SG), and enteric nervous system (ENS)) was investigated using immunohistochemistry. A subpopulation of large-sized neurons in DRG of 9 and 12 weeks old embryos showed immunoreactivity (IR), whereas the sympathetic ganglia or enteric neurons did not. In adults, neurocalcin IR was restricted to a subpopulation of large (13%) and intermediate (15%) sized neurons in DRG. The protein was also found in muscular (67%) and cutaneous (12%) nerve fibers, as well as in the axons supplying muscular (muscle spindles, Golgi's tendon organs, and perimysial Pacinian corpuscles) and cutaneous (Meissner's but not Pacinian corpuscles) mechanoreceptors, as well as motor end-plates. Present results demonstrate that neurocalcin in both developing and adult humans can be used as a specific marker for a subpopulation of sensory neurons coupled to proprioception and touch, and for axons of motoneurons forming motor end-plates.

Adult↗
PubMed1998

Pregnancy-induced denervation of the human uterine artery correlates with local decrease of NGF and TrkA.

Pregnancy induces transient and reversible denervation of the mammalian uterus and uterine artery which origin remains still unclear. It is well established that the density of sympathetic innervation is regulated by the levels of peptidergic diffusible growth factors, especially nerve growth factor (NGF). Whether a decrease of NGF and/or its signal-transducing receptor TrkA are involved in this physiological denervation of the uterine artery during pregnancy has not been analyzed. The aim of the present study is to analyze this topic on human uterine artery using ELISA, Western blotting and immunohistochemistry (associated to quantitative image analysis). The material was obtained from surgical pieces (hysterectomy) of non-pregnant and pregnant women from 4 to 16 weeks of gestation. The density of innervation for tyrosine hydroxylase assessed in whole mount samples of uterine artery, as well as the density of nerve fibers identified with other general nerve (PGP 9.5 and NFP) or Schwann cell (S-100 protein) markers was significantly reduced (p<0.05) in the uterine artery from pregnant woman. On the other hand, the tissular levels of NGF, the density of TrkA, and the immunostaining for both NGF and TrkA, were significantly reduced in uterine arteries from pregnant patients. These results strongly suggest that the physiological denervation occurring in the uterine artery during pregnancy is related to a decrease in the availability of NGF by nerve fibers, and to the impossibility to mediate its effect due to a remarkable decrease in the signal-transducing TrkA receptor.

Adult↗
PubMed1996

Calretinin immunoreactivity in human sympathetic ganglia.

Calretinin is an "EF-hand" calcium-binding protein involved in the maintenance of intracellular calcium ion homeostasis. This study was undertaken to investigate the presence of calretinin in human lumbar paravertebral sympathetic ganglia from subjects of different ages (26-85 years) using immunohistochemical and immunoblotting methods. Calretinin-like immunoreactivity was found in a subpopulation of postganglionic sympathetic neurons, whose percentage decreased progressively with aging by about 50% (63% of immunoreactive neurons at < or = 40 years; 29% at > or = 81 years) whereas the neuronal density remained basically unchanged. Calretinin-like immunoreactivity showed a granular pattern of cytoplasmic distribution suggesting preferential localization of this protein associated with intracellular membranes. Occasionally diffuse cytosolic labelling was also observed. The immunoblotting demonstrated a protein band with an estimated molecular weight of 30 kDa, approximately. Present results provide, for the first time, evidence for the presence of calretinin in human paravertebral sympathetic ganglia. Since the number of calretinin-like immunoreactive neurons decreased significantly with aging our findings suggest an involvement of this protein in the age-dependent impairment of sympathetic function.

Adult↗