安氏Ⅲ类错畸形病因的logistic分析

目的研究引起安氏Ⅲ类错牙合畸形的病因。方法对50例安氏Ⅲ类错牙合患者和50例正常牙合人作病因问卷调查,将结果用logistic法分析,提取有效病因。结果共有慢性扁桃体炎、遗传因素、咬上唇3项病因进入方程。结论按贡献大小,长期慢性扁桃体炎、经常咬上唇和遗传因素是导致安氏Ⅲ类错牙合畸形的危险因素。     

Pitfalls in diagnosis of aortic dissection by angiography: Algorithmic approach utilizing CT and MRI

Dissection of the thoracic aorta is a life-threatening event requiring imaging studies to define the level of the tear and the intinmal flap. The “gold standard” has been angiography. This method may fail to demonstrate the dissection, however, due to overlap of the true and false lumens or a very thin flap that is imaged en face rather than tangentially. Computed tomography has a diagnostic accuracy of 95%, but can fail to image the dissection due to technical factors or a thrombosed false hunen. Magnetic resonance imaging requires a hemodynamically stable and cooperative patient. A diagnostic algorithm is proposed for diagnosis of aortic dissection based on renal function and the surgeon's imaging modality preference.     

Inhibition of neurally-evoked transmitter release by calcium channel antagonists in rat parasympathetic ganglia.

1. Excitatory postsynaptic potentials (e.p.s.ps) were recorded from the submandibular parasympathetic ganglia of newborn rats (10-20 days old), by intracellular microelectrode recording and a suction electrode to deliver stimulus trains to the lingual nerve (15 stimuli at 0.1, 0.3, 1, 3, and 10 Hz, 22 degrees C). Only evoked responses without voltage-dependent action potentials were analyzed (observed at membrane potentials negative to -70 mV), and e.p.s.p. amplitudes were determined for the plateau responses during each train (5-15th response). 2. Cadmium, an inorganic calcium channel antagonist, reduced e.p.s.p. amplitudes in a dose-dependent manner (Kd 74 microM, P less than 0.01). Nickel (1-300 microM) did not attenuate the amplitude of evoked responses. 3. Verapamil (0.1-30 microM), a phenylamine, had no significant effects upon e.p.s.p. amplitudes at any frequency examined. Higher concentrations of verapamil (100 microM) blocked neurally evoked responses in a manner consistent with the antagonism of voltage-sensitive sodium currents. 4. Diltiazem, a benzothiazepine, reduced e.p.s.p. amplitudes in a dose-dependent manner, the depression being accentuated at high stimulation frequencies (80% block at 30 microM and 10 Hz). The pure (-)-cis enantiomer of diltiazem (10-30 microM) was without effect. 5. Amlodipine, a 1,4-dihydropyridine, did not antagonize synaptic transmission at any stimulus frequency examined (10-30 microM, 0.1-10 Hz, n = 3). 6. Amiloride, a potassium-sparing diuretic, depressed the amplitudes of evoked responses in a dose-dependent manner (one-site Kd 31 microM, P less than 0.005), although the extent of the block was alleviated with high stimulus frequencies. The effects of 30 microM amiloride were unlikely to be of post-synaptic origin as both the amplitudes of miniature e.p.s.ps, and the iontophoretic potentials induced by exogenous acetylcholine, were not attenuated by treatment with this compound. The amiloride derivative, 3',4'-dichlorobenzamil was ineffective in reducing the amplitude of e.p.s.ps (30-100 microM). 7. omega-Conotoxin GVIA, a marine neurotoxin, which depressed whole cell calcium currents recorded from cultured rat parasympathetic cardiac neurones (up to 90% block at 10 nM), was ineffective at blocking synaptic transmission in submandibular ganglia (0.1-1 microM). 8. The differential effects of these calcium channel antagonists upon synaptic transmission in rat parasympathetic ganglia, suggest that either more than one type of calcium channel may be involved in transmitter release, or that the presynaptic calcium channels possess pharmacological sensitivities different from those of channel types described in ne     

Malignant angioendotheliosis involving the nervous system: support for a lymphoid origin of the neoplastic cells.

The clinical and post mortem findings of a case of malignant angioendotheliosis are described. The patient presented with neurological signs attributable to repeated episodes of cerebral and spinal cord infarction. Histological examination showed multifocal intravascular proliferation of mononuclear cells. Immunocytochemical characterisation of these neoplastic cells supports the recent suggestion that this disease represents an unusual form of intravascular lymphoma, which appears to show a predilection for blood vessels of the nervous system.     

Does substance P act as a pain transmitter?

Pain signals appear to be transmitted by a variety of chemicals. Masanori Otsuka and Mitsuhiko Yanagisawa review evidence that substance P, present in 10–20% of primary afferent fibers, is one such transmitter. In the isolated CNS preparations of the newborn rat the tachykinin antagonist spantide reversibly depresses nociceptive C-fiber reflexes of slow-time course without affecting the monosynaptic reflex. These observations together with other lines of evidence suggest that SP serves as a transmitter in a subpopulation of primary afferent C-fibers and produces slow excitatory postsynaptic potentials in second-order neurons in the dorsal horn to transmit delayed pain signals to the CNS.