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Biomedical subjects

G Giannakopoulos

Publications and source records attributed to G Giannakopoulos.

10 recordsLinked to original sources

Leukocytoclastic vasculitis: is propranolol implicated?

Drugs frequently cause cutaneous adverse reactions. The suspected agent is sometimes difficult to identify, especially in patients receiving multidrug treatment and with underlying illnesses that may contribute to the clinical picture. In our patient, propranolol-induced leukocytoclastic vasculitis was diagnosed by exclusion.

Adrenergic beta-Antagonists↗

Effects of mesulergine treatment on diet selection, brain serotonin (5-HT) and dopamine (DA) turnover in free feeding rats.

1. The effects of mesulergine, a 5-hydroxytryptamine (5-HT) receptor antagonist with dopamine (DA) agonistic properties, on rats diet selection over a seven day period and on 5-HT and DA turnover was studied. 2. Three groups of male Wistar rats were individually caged and ad libitum fed with a standard (SD) and 50% sweet carbohydrate enriched diet (CED). Food intake was measured daily 4 hrs and 24 hrs after i.p. injections of mesulergine (1 and 3 mg/kg) or vehicle. 5-HT and 5-HIAA in hypothalamus (Hy), Striatum (St) and hippocampus (Hi) as well as DA and DOPAC in (Hy) and (St) were assayed at the 8th day of the experiment. 3. There was a dose dependent increase of SD consumption 4 hrs after mesulergine treatment while the CED remained unchanged with total food intake dose dependently increased as a consequence. At 24 hrs measurements SD consumption was increased only for the dose of 1 mg/kg of mesulergine, while a dose dependent decrease of CED intake was observed. Total food intake was unchanged for the dose of 1 mg/kg and decreased with the dose of 3 mg/kg consequently. A dose dependent decrease of rats body weight was observed too. 4. A significant increase of 5-HIAA/5-HT ratio in (Hy) and (St) for the dose of 1 mg/kg and in (Hi) for the dose of 3 mg/kg with no changes of DA turnover were found. 5. The above data suggest a dual mode of action of mesulergine presented as a short term hyperphagia due to simultaneous antiserotonergic and dopaminergic activity and long-term hypophagia due to long-term agonistic effects of dopaminergic neurons.

Animals↗

Surgical management of radiated scalp in patients with recurrent glioma.

Patients with malignant brain tumors requiring multiple craniotomies and external beam radiotherapy are at risk of scalp wound breakdown secondary to fibrosis and radiation damage. We present three cases to illustrate the nature of the problem and the surgical approaches to scalp repair. When a bicoronal incision has been used for the initial craniotomy, the plastic repair can be performed with a bipedicle visor scalp flap and split-thickness skin graft to cover the pericranium at the donor site. When a curvilinear (U-shaped or horseshoe) flap has been used for the initial craniotomy, a single-pedicle flap may be rotated to achieve closure without tension. In anticipation of the risk of scalp wound breakdown in patients with malignant brain tumors, the planning of the operative incision for the first craniotomy needs to take into account the long-term viability of the scalp. We recommend linear scalp incisions parallel to the arterial distribution instead of the traditional curvilinear (U-shaped or horseshoe) flaps; linear incisions are less likely to break down, and in the event of breakdown, linear wounds offer better therapeutic surgical options for plastic repair.

Adult↗

Implications for the pathogenesis of aneurysm formation: metastatic choriocarcinoma with spontaneous splenic rupture. Case report and a review.

We report a case of ruptured intracranial aneurysm from metastatic choriocarcinoma in a patient presenting with intracerebral hemorrhage. Operative evacuation of the hematoma with clipping of a distal right middle cerebral artery aneurysm was performed. Postoperatively, the patient developed hypovolemic shock from spontaneous splenic rupture. Histopathologic examination of the cerebral aneurysm showed choriocarcinoma invading the vessel wall. Metastatic choriocarcinoma should be considered in the differential diagnosis of intracerebral or subarachnoid hemorrhage in women of child-bearing age.

Adult↗

Culture of human sebocytes and markers of sebocytic differentiation in vitro.

Human sebocytes obtained as explants after in vitro culture of isolated sebaceous glands were recently shown to maintain in part a sebocytic differentiation. The aim of this study was to further identify markers of sebocytic differentiation in vitro. Therefore, the morphology of cultured human sebocytes, and their differentiation with lipid storing and expression of cellular proteins were investigated by microscopy, electron microscopy, study of cell kinetics, cytochemistry and immunocytochemistry, and were compared to cultured human keratinocytes obtained from the same skin specimens. At first, sebocytes in all stages of sebocytic differentiation were detected in vitro. Abundant cytoplasmic lipids and the absence of desmosomes were identified as their ultrastructural characteristics. Secondly, an increasing number of sebocytes storing lipids was detected during cell proliferation. Sebocytes contained up to 4 times more lipids than keratinocytes in vitro. Squalene and increased quantities of wax/sterol esters could be extracted from secondary sebocyte cultures. Thirdly, the monoclonal antibodies 6B10 (keratin 4), RPN1162 (keratin 7), and OM-1 labeled only sebocytes in vitro. Furthermore, sebocytes presented a marked expression of keratin 19 in comparison to keratinocytes, as detected with CK 4.62, and a lack of RPN1161 (keratins 1 and 2) expression, which was typically found to be expressed in cultured keratinocytes. The culture of human sebocytes possessing several characteristics of sebocytic differentiation in vivo offers unique possibilities in investigating direct effects on sebaceous cell growth, differentiation and their regulation.

Antibodies, Monoclonal↗