空管药物疗法治疗牙髓病和根尖周病疗效观察

用ＳＭＴＤ复合药物对牙髓病和根尖周病实施空管药物疗法。７８例１０３颗获得完整随访资料患牙经两年观察，９２．２％治愈率。文章介绍了治疗方法，讨论了空管药物疗法的愈合机理、优点、失败原因及其预防措施。     

Influence of peripheral afferents on cortical and spinal motoneuron excitability.

The objective of this study was to establish to what extent muscle, cutaneous, and joint afferents alter the excitability of spinal and cortical motor neurons. This question was examined by studying the impact of electrical stimulation of the second and third digits, the median nerve at the wrist, and the recurrent thenar motor branch on the F/H and magneto-electrical cortical motor responses (MEPs) of the thenar muscles. The firing frequencies of single F/H motor unit action potentials were unaltered by the foregoing conditioning peripheral stimuli. MEPs conditioned by motor threshold stimulation of the median nerve at the wrist or the recurrent motor branch were significantly increased in size at conditioning to test intervals of 50 to 80 milliseconds. No significant change in MEP size resulted from conditioning stimulation of the digital nerves. We conclude that muscle afferents were primarily responsible for the increase in MEP size. Conditioning stimuli may allow examiners to assess central motor conduction where it would otherwise be impossible.     

Cardiac metabolism: A technical spectrum of modalities including positron emission tomography,single-photon emission computed tomography,and magnetic resonance spectroscopy

Noninvasive techniques for the assessment of cardiac metabolism are important for the detection of potentially salvageable tissue in jeopardized areas of the myocardium. The correct identification of hibernating and stunned myocardium in patients with severely depressed cardiac function can have vital therapeutic consequences for the patient. Changes in myocardial fatty acid and glucose metabolism during acute and prolonged ischemia can be traced by positron-emitting or gamma-emitting radiopharmaceuticals. Alternatively,³¹P-labeled magnetic resonance spectroscopy can be used for the assessment of high-energy phosphate metabolism. It is not yet clear which modality will emerge as the most useful in the clinical setting. Positron emission tomography (PET) that uses combinations of flow tracers and metabolic tracers offers unique opportunities for quantification and high-resolution static and rapid dynamic studies. Currently, assessment of glucose metabolism with¹⁸F-fluorodeoxyglucose is regarded as the gold standard for myocardial viability and prediction of improvement of impaired contractile function after revascularization. However, preserved oxidative metabolism may be required for potential functional improvement, and therefore assessment of residual oxidative metabolism by¹¹C-labeled acetate PET may prove to be more accurate than¹⁸F-fluorodeoxyglucose PET, which reflects both anaerobic and oxidative metabolism. Moreover, because fatty acids are metabolized only aerobically, they are excellent candidates for the clinical assessment of myocardial viability and prediction of functional improvement after revascularization. Especially derivatives of fatty acids that are not metabolized but accumulate in the myocyte are attractive for myocardial imaging. Examples are¹²³I-beta-methyl-p-iodophenyl pentadecanoic acid and 15-(o-¹²³I-phenyl)-pentadecanoic acid. These tracers can be detected by planar scintigraphy and single-photon emission computed tomography, which are more economical and widely available than PET. In addition, 511 keV collimators have been developed recently, making the detection of positron emitters by planar scintigraphy and single-photon emission computed tomography feasible. The experience with³¹P-labeled magnetic resonance spectroscopy in humans is still limited. With current magnetic resonance spectroscopic techniques, insufficient spatial resolution is achieved for clinical purposes, but the possibility of serial measurements to monitor rapid changes of phosphate-containing molecules in time makes magnetic resonance spectroscopy very valuable for the research of myocardial metabolism.     

Preliminary assessment of fluorine-18 fluorodeoxyglucose positron mission tomography in patients with bladder cancer

The purpose of this study was to assess the feasibility of imaging of bladder cancer with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. We studied 12 patients with histologically proven bladder cancer who had undergone surgical procedures and/or radiotherapy. Retrograde irrigation of the urinary bladder with 1000–3710 ml saline was performed during nine of the studies. Dynamic and static PET images were obtained, and standardized uptake value images were reconstructed. FDG-PET scanning was true-positive in eight patients (66.7%), but false-negative in four (33.3%). Of 20 organs with tumor mass lesions confirmed pathologically or clinically, 16 (80%) were detected by FDG-PET scanning. FDG-PET scanning detected all of 17 distant metastatic lesions and two of three proven regional lymph node metastases. FDG-PET was also capable of differentiating viable recurrent bladder cancer from radiation-induced alterations in two patients. In conclusion, these preliminary data indicate the feasibility of FDG-PET imaging in patients with bladder cancer, although a major remaining pitfall is intense FDG accumulation in the urine. Present address: Department of Radiology, National Defense Medical College, 3-2 Namiki, Tokorozawa 359, Japan     

Fluorine-18-fluorodeoxyglucose positron emission tomography for preoperative parathyroid imaging in primary hyperparathyroidism

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed in seven consecutive patients with primary hyperparathyroidism to preoperatively locate parathyroid adenomas. Foci of FDG accumulation corresponding to abnormal parathyroid tissue were observed in two out of nine surgically excised parathyroid adenomas. It was concluded that FDG PET imaging demonstrated a too low sensitivity for systematic preoperative detection and localization of parathyroid glands causing primary hyperparathyroidism.     

Myoblast fusion in Drosophila melanogaster is mediated through a fusion-restricted myogenic-adhesive structure (FuRMAS).

During myogenesis in Drosophila embryos, a prominent adhesive structure is formed between precursor cells and fusion-competent myoblasts (fcms). Here, we show that Duf/Kirre and its interaction partners Rols7 (found in founder myoblasts and growing myotubes) and Sns (found in fcms) are organized in a ring-structure at the contact points of fcms with precursor cells, while cytoskeletal components like F-actin and Titin are centered in this ring in both cell types. The cytoplasmic protein Blow colocalizes with the actin plugs in fcms after cell adhesion. Furthermore, the requirement of additional as yet unidentified components was demonstrated by using mammalian C2C12 myoblasts. In this study, we propose that the fusion-restricted myogenic-adhesive structure (FuRMAS) is pivotal in linking cell adhesion as well as local F-actin assembly and dynamics to downstream events that ultimately lead to plasma membrane fusion. Moreover, we suggest that the FuRMAS may restrict the area of membrane breakdown.     

PET-CT在恶性肿瘤诊断中的初步应用

目的探讨PET-CT一体机在恶性肿瘤中的应用价值.方法收集已经明确诊断的全身不同部位的恶性肿瘤病例62例,经PET-CT检查后进行回顾性分析,采用目测和半定量分析方法.结果62例肿瘤病人共检出142个病灶,PET图像阳性率93.55%(58/62);PET图像阴性率6.45%(4/62);PET发现病灶而CT未完全发现病灶率19.4%(12/62);CT发现而PET未见浓聚率6.45%(4/62);原发灶未能找到率1.61%(1/62).标准化摄取值(SUV)大于2.5占78.2%(111/142);SUV2.5～2.0占14.8%(21/142);SUV小于2.0占7%(10/142).结论PET-CT与单纯PET,CT比较具有明显的优势,可以精确定位、定性,但PET-CT也有一定的局限性.     

Synthesis of 4‐[18F]fluoroiodobenzene and its application in sonogashira cross‐coupling reactions

The first application of a Sonogashira cross‐coupling reaction in ¹⁸F chemistry has been developed. The reaction was exemplified by the cross‐coupling of terminal alkynes (ethynylcyclopentyl carbinol 6 , 17α‐ethynyl‐3,17β‐estradiol 7 and 17α‐ethynyl‐3‐methoxy‐3,17β‐estradiol 8 ) with 4‐[¹⁸F]fluoroiodobenzene. 4,4′‐Diiododiaryliodonium salts were used as precursors for the synthesis of 4‐[¹⁸F]fluoroiodobenzene, enabling the convenient access to 4‐[¹⁸F]fluoroiodobenzene in 13–70% yield using conventional heating or microwave activation. The Sonogashira cross‐coupling of 4‐[¹⁸F]fluoroiodobenzene with terminal alkynes gave the corresponding 4‐[¹⁸F]fluorophenylethynyl‐substituted compounds [¹⁸F]‐9 , [¹⁸F]‐10 and [¹⁸F]‐13 in yields up to 88% within 20 min of starting from 4‐[¹⁸F]fluoroiodobenzene. Copyright © 2003 John Wiley & Sons, Ltd.     

Relationship between apoptosis and proliferation in secondary tumors of the brain

A correlation between apoptosis and proliferation in astrocytomas and oligodendrogliomas, but not in glioblastomas, has been previously reported. An index for apoptosis and proliferation was established for each tumor in a series of 20 brain metastases, and its correlation was studied using the Spearman rank correlation test. Apoptosis index (AI) ranged between 1 and 78% (mean ± SD: 11.48 ± 16.4). Proliferation index (PI) ranged between 2.4 and 21% (mean ± SD: 8.23 ± 4.8). When the relationship between AI and PI was studied, a clear correlation was found (r: 0.8965, 95% CI: 0.74–0.95; P < 0.0001). Therefore, it is concluded that a clear correlation exists between proliferation and apoptosis in secondary tumors of the brain.     

Whole-Body [18F]FDG PET in the Management of Metastatic Brain Tumours

Summary Background To determine its roles in the diagnosis and the systemic evaluation of metastatic brain tumours, whole-body positron emission tomography (PET) using [¹⁸F]FDG was performed in 20 consecutive patients. Methods  All patients were thought to be suffering or needing to be differentiated from metastatic brain tumours. Nine patients had multiple brain lesions; six were older and showed a rim-enhancing lesion with surrounding oedema; seven had homogeneously enhancing periventricular lesion(s) on computed tomography (CT) and/or magnetic resonance (MR) imaging, thought to be central nervous system lymphomas. Two patients had skull mass(es) and two patients had a solid mass suspected to be, respectively, a haemorrhagic metastasis and a metastatic malignant melanoma. All of them received whole-body [¹⁸F]FDG PET and conventional systemic work-up for metastasis in order to compare the results of the two methods. Results  Metastatic brain tumours were diagnosed on whole-body [¹⁸F]FDG PET in eleven patients who had extracranial and intracranial hypermetabolic lesions. In nine of these, a conventional work-up also detected primary lesions which on whole-body [¹⁸F]FDG PET were seen to be hypermetabolic foci. Systemic lymph node metastases were detected by whole-body [¹⁸F]FDG PET only in two patients and histological diagnosis was possible by biopsy of lymph nodes rather than of brain lesions. In the remaining nine patients who had only intracranial hypermetabolic foci, histological diagnosis was made by craniotomy or stereotactic biopsy. It was confirmed that seven of nine patients were suffering from a primary brain tumour and two from metastatic carcinoma. None of the nine showed evidence of systemic cancer on conventional work-up. Histological diagnoses of the primary brain tumours were four cases of primary central nervous system lymphoma and one each of multifocal glioblastoma, Ewing's sarcoma, and cavernous angioma.  Patients felt no discomfort during the whole-body [¹⁸F]FDG PET procedure and there were no complications. The false negative rate in [¹⁸F]FDG PET and in conventional work-up was 15.4% and 30.7% respectively. There were no false positives on either [¹⁸F]FDG PET or conventional work-up. Conclusion  It is suggested that whole-body [¹⁸F]FDG PET is a safe, reliable, and convenient method for the diagnosis and systemic evaluation of patients thought to be suffering or needing to be differentiated from a metastatic brain tumour.