Dopamine D-1 receptor-mediated inhibition of nucleus accumbens neurons from the ventral tegmental area.

1. Spike generation by stimulation of the parafascicular nucleus of thalamus was extracellularly recorded in the nucleus accumbens of chloral hydrate-anesthetized adult Wistar rats using a silver-wire microelectrode attached along a seven-barreled micropipette, each of which was filled with dopamine, SKF 38393 (D-1 agonist), bromocriptine (D-2 agonist), haloperidol, SCH 23390 (D-1 antagonist) and domperidone (D-2 antagonist). The drugs were microiontophoretically applied to the target neurons recorded. 2. Effects of dopamine receptor antagonists on the inhibition of the spike generation by conditioning stimuli applied to the ventral tegmental area preceding the test stimulus to the parafascicular nucleus and those of dopamine agonists on the test stimulus-induced spikes were examined. 3. The parafascicular nucleus stimulation-induced spikes were inhibited by dopamine as well as D-1 and D-2 agonists and by the conditioning stimulation of the ventral tegmental area. The conditioning stimulation-induced inhibition was antagonized by haloperidol and SCH 23390, but not by domperidone. 4. Activation of D-1 receptors, which make probably synaptic contact with dopaminergic nerve terminals from the ventral tegmental area, is considered to result in inhibition of the neuronal activity of the nucleus accumbens neurons receiving input from the parafascicular nucleus of the thalamus. In addition, D-2 receptors located extrajunctionally may be involved in the inhibition of the same neurons in the nucleus accumbens.     

A surgical case of aortic regurgitation with Beh?et disease

A case of Beh?et disease associated with aortic valve regurgitation treated with aortic valve replacement is reported. The patient was treated successfully with special surgical techniques for prevention of post operative paravalvular leakage and occurrence of pseudo aneurysm because the patient was under long-term steroid therapy for Beh?et disease.     

A case of area-specific stimulus-sensitive postanoxic myoclonus.

The authors report a case of area-specific stimulus-sensitive postanoxic myoclonus and discuss possible pathophysiology. A 71-year-old man sustained cardiorespiratory arrest that lasted 10 minutes and remained unresponsive. On the first EEG obtained 8 hours after the arrest there was no cerebral electrical activity before stimulation of the trigeminal-innervated areas. Periorbital stimulation was associated with bursts of spike-wave activity and generalized myoclonic jerks, whereas other types of stimulation did not elicit any response. A second EEG obtained 32 hours later showed a nonreactive alpha coma pattern. The patient died 7 days after the arrest. Area-specific stimulus-sensitive postanoxic myoclonus is very rare. The regularity of generalized bursts of spike-wave activity (cortical response) in response to stimulation of trigeminal-innervated areas suggests that the resting EEG electrocerebral silence may have been a result of cortical suppression with disinhibition of stimulus-sensitive brainstem-generated myoclonus.     

慢性肾脏病-矿物质和骨代谢异常的研究进展

慢性肾脏病-矿物质和骨代谢异常(CKD-MBD)不仅提高心血管疾病的发生率,也是致死、骨折、生活质量下降及骨外组织钙化的重要原因。本文综述了CKD-MBD的发生机制、临床诊断、治疗措施三个方面的最新研究进展。     

Surgical treatment of the aseptic femoral shaft nonunion

Femoral shaft nonunions is difficult complication and a big challenge for the orthopaedic surgeons. These complications occur after open femoral fractures, comminuted fractures, segmental fractures, the infection, after the inadequate fixed osteosynthesis, the systemic disease, and smokers. The paper presents the results of treatment aseptic femoral shaft nonunion in 18 patients. They were primarily operated by the method of internal compresive plate fixation and external fixation (open fractures). For fixation we used dinamic internal fixator by Mitkovic. All nonunions treated by this method are healed. In patients with atrophic femoral shaft nonunions in addition to fixation was performed and bone grafting. This implant has proved successful in the treatment of femoral shaft nonunion. During the fixation no periostal and intramedullary vascularization damage, which is an important prerequisite for bone healing. Implant enables biological and mechanical conditions for nonunion healing.     

Preoperative preparation of pregnant women

All the elective surgeries are to be avoided during pregnancy and pregnant women should undergo only emergency surgical interventions. Pregnancy is associated with different physiological changes in the organism, which should be taken into account in preparative preparation of the pregnant women. Expanded body fluid volume leads to dilutional anemia, however other hematological disorders may be present as well. Extreme obesity is a frequent comorbidity, while hypertension is associated with the highest risks since it may lead to a life-threatening complication--eclampsia. As for other coexisting diseases, urinary tract infections and gestational diabetes are the most common as well as hyperthyroidism and other diseases that may also develop. The type and severity of the acute surgical disease, extensiveness of the planned surgery as well as the type of planned anesthesia to be applied, occasionally necessitate, depending on the gestational age, termination of pregnancy to be considered. Gynecological-obstetric consultations are mandatory in all surgical interventions planned in pregnant women.