Transcranial doppler waveform differences in hyperemic and nonhyperemic patients after severe head injury

Although increased cerebral blood flow velocity is readily measured by transcranial doppler ultrasonography (TCD), the causes of the velocity elevation may differ. After severe head injury, increased blood flow velocity can develop both in patients with global hyperemia (suggestive of vasodilation) and in those without hyperemia (suggestive of vasospasm). The present study attempts to determine whether TCD can differentiate these two mechanisms of velocity increase.

Fourteen severely brain-injured patients who developed increased middle cerebral artery blood flow velocity (time-averaged mean velocity > 100 cm/s) were studied. Eight cases were nonhyperemic and six were hyperemic as defined by arterial-jugular venous oxygen content differences of more than 4 mL/dL and less than 4 mL/dL, respectively. The TCD waveform of all eight nonhyperemic cases showed a diastolic notch, which was absent in all six hyperemic patients (p = 0.00066). TCD waveform profile appears to provide a noninvasive means of differentiating at the bedside the two causes of increased flow velocity. If associated with raised intracranial pressure, these require different treatment.     

高位腰椎间盘突出症

目的：通过147例高位腰椎间盘突出症的回顾性研究,旨在提高对本症的认识,减少漏诊,误诊,方法：回顾性分析报告147例高位腰椎间盘突出,结果：治疗腰1,210例,腰2。3 32例,腰3,4 105例,其中双间隙突出34例,跳跃性突出27例,伴椎管狭窄31例。瘫痪3例,非手术治疗34例,手术113例,优47例,良8例,差92例,重点讨论了高位腰椎及椎间盘和神经根的解剖特点和临床三大特征及诊断治疗,提出对不同程度的病人用不同治疗方式以及手术中需要注意的六个问题。     

In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Pulmonary arteriovenous malformations: techniques and long-term outcome of embolotherapy

Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.     

Inpatient admissions for interventional radiology: philosophy of patient management

As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.     

Comparison of the efficacies of five different statins on inhibition of human saphenous vein smooth muscle cell proliferation and invasion

Statins (HMG-CoA reductase inhibitors) exhibit beneficial effects on the vasculature independently of their cholesterol-lowering properties. These pleiotropic effects underlie the ability of statins to reduce intimal hyperplasia in saphenous vein (SV) bypass grafts by attenuating smooth muscle cell (SMC) invasion and proliferation. Although all statins can effectively lower cholesterol, the pleiotropic effects of individual statins may well differ. We therefore compared the concentration-dependent effects of 4 lipophilic statins (simvastatin, atorvastatin, fluvastatin, and lovastatin) and 1 hydrophilic statin (pravastatin) on the proliferation and invasion of SMC cultured from SV of 9 different patients undergoing coronary artery bypass grafting (CABG). The lipophilic statins inhibited SV-SMC proliferation over a 4-day period with an order of potency of fluvastatin > atorvastatin > simvastatin > lovastatin (IC50 range = 0.07 to 1.77 microM). Similarly, these statins also inhibited SV-SMC invasion through an artificial basement membrane barrier (fluvastatin > atorvastatin > simvastatin > lovastatin; IC50 range = 0.92 to 26.9 microM). In contrast, the hydrophilic pravastatin had no significant effect on SV-SMC proliferation at concentrations up to 10 microM, nor did it attenuate SV-SMC invasion (up to 30 microM). Our data provide strong evidence that individual statins possess differential pleiotropic effects on SV-SMC function. This may be of clinical relevance in the selection of individual statins for the treatment of CABG patients.     

When beef primes reef more than leaf: Orthographic information affects phonological priming in spoken word recognition

This study was designed to investigate orthographic effects on spoken word recognition by combining the priming paradigm with a measure of event-related brain potentials (ERPs). Primes and targets either shared both orthography and phonology of the rhyme ( beef-reef ) or they shared rhyme phonology only ( leaf-reef ). The two "related" conditions were compared against an "unrelated" condition ( sick-reef ). The results revealed a significant orthographic priming effect that was present on the early part of the N400 and that occurred as early as the phonological priming effect itself. Importantly, phonological and orthographic priming effects had different topographic distributions: The phonological priming effect was localized over centro-posterior regions, whereas the orthographic priming effect was more anterior. These results support a theory according to which orthographic information is coactivated online in spoken word recognition.