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D Park

Publications and source records attributed to D Park.

142 records · Page 8Linked to original sources
PubMed1976

Immunohistochemical studies on the localization and distribution of monoamine neuron systems in the rat brain. I. Tyrosine hydroxylase in the mes- and diencephalon.

The localization and distribution of tyrosine hydroxylase (TH), the first enzyme in the catecholamine synthesis, in the mes- and diencephalon has been studied with the indirect immunofluorescence technique of Coons and collaborators. Principally, TH was present in neuron systems with a distribution similar to known dopamine, noradrenaline and adrenaline systems. The present data, taken together with published and some unpublished results, indicate that all parts of most central dopamine neurons, i.e. cell body, dendrites, axon and nerve terminals, appear strongly fluorescent. The adrenaline neurons also appeared strongly fluorescent, except for their axons, which only exhibited a weak fluorescence. Only cell bodies of noradrenaline neurons were strongly fluorescent, whereas the nerve terminals and axons showed a weak or moderate fluorescence intensity. The fine noradrenaline nerve terminals in some areas, such as the thalamus, were invisible or, under favourable conditions, weakly fluorescent. Therefore, in the present study we are mainly dealing with the dopamine neurons of the upper brain stem. Our results demonstrate a widespread occurrence of TH-positive neuron systems in the mes- and diencephalon. The different mesencephalic dopamine systems and their ascending projections were visualized. Numerous TH-positive cell bodies were present along the ventricle system extending from the aqueductus cerebri to the most cranial periventricular parts of the third ventricle. The caudal part of these neurons, consisting of very small cell bodies, belong to the dorsal periventricular system described by Lindvall and Björklund. Several TH-positive cell bodies were also observed in the inferior collicle of young animals. In the superficial layers of the inferior collicles TH positive nerve terminals were seen. At the hypothalamic level the A11 to A14 cell groups as well as some additonal cell bodies and extensive nerve terminal plexuses appeared strongly fluorescent. The differences in the intensity of the TH-related immunofluorescence between various brain regions and between various neuron systems may well reflect differences in enzyme levels between the various catacholamine systems rather than be due to the existence of different types of TH.

Adrenergic Fibers↗
PubMedDate not supplied

Legionella micdadei prosthetic valve endocarditis.

Legionella usually causes pneumonia, but occasionally is in the differential diagnosis of "culture negative endocarditis" which sometimes involves prosthetic heart valves. Legionella prosthetic valve endocarditis is nearly always due to Legionella pneumophila and its clinical presentation is indistinguishable from other causes of prosthetic valve endocarditis. Diagnosis of Legionella prosthetic valve endocarditis is by recovery of the organism from the blood, demonstration or isolation of the organism from the prosthetic heart valve, or by persistently high Legionella titers which are extremely elevated in prosthetic valve endocarditis compared to Legionella pneumonia. We believe this is the first case reported of prosthetic valve endocarditis caused by Legionella micdadei, and the first case of Legionella prosthetic valve endocarditis with microscopic hematuria.

Aged↗
PubMedDate not supplied

A polymorphism of the XRCC1 gene predicts for response to platinum based treatment in advanced colorectal cancer.

Recently, it has been demonstrated that the Arg399Gln substitution in the XRCC1 gene is associated with increased levels of markers of DNA damage. Deficiency in DNA repair pathways has been shown to confer to resistance to several drugs, including platinum compounds. Here we have studied whether this polymorphism of the XRCCI gene will predict response and survival of patients with metastatic colorectal cancer treated with oxaliplatin and 5-FU. Sixty-one patients received a combination of 130 mg/m2 oxaliplatin and continuous infusion 5-FU. The XRCC1 polymorphism was evaluated using a RFLP method. We found 73% (8/11) of responders had an Arg/Arg genotype and three were heterozygous, but 66% (33/50) of non-responders showed a Gln/Gln or Gln/Arg genotype (p=0.038). Patients carrying at least one Gln mutant allele were at a 5.2 (95%CI: 1.21,22.07) fold increased risk to fail the 5-FU/oxaliplatin chemotherapy. The data suggest that the polymorphism in exon 10 of the XRCC1 gene may be associated with resistance to oxaliplatin/5-FU chemotherapy in advanced colorectal cancer.

Adenocarcinoma↗