18F-FDG PET and PET/CT in fever of unknown origin.

Fever of unknown origin (FUO) was originally defined as recurrent fever of 38.3 degrees C or higher, lasting 2-3 wk or longer, and undiagnosed after 1 wk of hospital evaluation. The last criterion has undergone modification and is now generally interpreted as no diagnosis after appropriate inpatient or outpatient evaluation. The 3 major categories that account for most FUOs are infections, malignancies, and noninfectious inflammatory diseases. The diagnostic approach in FUO includes repeated physical investigations and thorough history-taking combined with standardized laboratory tests and simple imaging procedures. Nevertheless, there is a need for more complex or invasive techniques if this strategy fails. This review describes the impact of (18)F-FDG PET in the diagnostic work-up of FUO. (18)F-FDG accumulates in malignant tissues but also at the sites of infection and inflammation and in autoimmune and granulomatous diseases by the overexpression of distinct facultative glucose transporter (GLUT) isotypes (mainly GLUT-1 and GLUT-3) and by an overproduction of glycolytic enzymes in cancer cells and inflammatory cells. The limited data of prospective studies indicate that (18)F-FDG PET has the potential to play a central role as a second-line procedure in the management of patients with FUO. In these studies, the PET scan contributed to the final diagnosis in 25%-69% of the patients. In the category of infectious diseases, a diagnosis of focal abdominal, thoracic, or soft-tissue infection, as well as chronic osteomyelitis, can be made with a high degree of certainty. Negative findings on (18)F-FDG PET essentially rule out orthopedic prosthetic infections. In patients with noninfectious inflammatory diseases, (18)F-FDG PET is of importance in the diagnosis of large-vessel vasculitis and seems to be useful in the visualization of other diseases, such as inflammatory bowel disease, sarcoidosis, and painless subacute thyroiditis. In patients with tumor fever, diseases commonly detected by (18)F-FDG PET include Hodgkin's disease and aggressive non-Hodgkin's lymphoma but also colorectal cancer and sarcoma. (18)F-FDG PET has the potential to replace other imaging techniques in the evaluation of patients with FUO. Compared with labeled white blood cells, (18)F-FDG PET allows diagnosis of a wider spectrum of diseases. Compared with (67)Ga-citrate scanning, (18)F-FDG PET seems to be more sensitive. It is expected that PET/CT technology will further improve the diagnostic impact of (18)F-FDG PET in the context of FUO, as already shown in the oncologic context, mainly by improving the specificity of the method.     

Optical penalization can improve vision after occlusion treatment

BACKGROUND: Optical penalization (OP) has previously been shown to successfully maintain vision in amblyopic eyes of older children when patching compliance is poor and when vision decreases once patching is discontinued. This study shows that the final vision in optically penalized eyes is often better than the vision obtained after patching alone. SUBJECTS AND METHODS: During the 5-year period from January 1992 to February 1997, 28 children aged between 3.7 and 8.2 years (average age, 6.5+/-1.1 years) were optically penalized for an average of 1.5+/-0.75 years. The maximum length of penalization was 3.3 years, whereas the minimum time was 6 months. There were 21 children with strabismic amblyopia and 7 children with anisometropic amblyopia. All 28 children had worn a patch to achieve their best visual levels and then had shown a loss of best vision when occlusion was stopped. Patching was usually resumed and continued until the previous best vision was obtained; at this point OP was started to "maintain" vision. Eighteen of the 28 children have discontinued penalization and have been followed up an average of 1(1/2) years. RESULTS: Twenty-six (93%) of the 28 patients showed an increase in best vision from that found at the conclusion of patching, and 2 patients maintained their vision at the initial level. The average visual acuity at the start of penalization was 20/50 (0.42+/-0.11 logarithm of the minimum angle of resolution [log MAR]). Final average visual acuity was 20/27 (0.15+/-0.12 log MAR). The average increase in vision was nearly 3 lines or 0.27+/-0.12 log MAR. CONCLUSION: OP alone (without the use of pharmacologic agents such as atropine) not only maintains vision after patching therapy, but also appears to improve the final visual outcome.     

青霉素高产菌株的推理选育

目的：筛选一株优良的抗生素产生菌。方法：通过人为诱变来动摇产生菌原有的严密控制机制。结果：得到一种抗生素生物合成能力异常的突变株。结论：此方法可过量合成人们所期望的抗生素。     

盐酸特拉唑嗪胶囊的稳定性研究

目的：考察盐酸特拉唑嗪胶囊的稳定性。方法：通过影响因素(强光照射、高温、高温)，加速和留样考察实验，以含量为测定指标，考察胶囊的含量变化。结果：在温度40℃、60℃、光照3500LX及RH75％等因素影响下，胶囊的含量无明显变化。结论：在25℃时，通过经典恒温加速试验推测盐酸特拉唑嗪胶囊的失效期为2年。     

Role of endogenous Schwann cells in tissue repair after spinal cord injury

Schwann cells are glial cells of peripheral nervous system, responsible for axonal myelination and ensheathing, as well as tissue repair following a peripheral nervous system injury. They are one of several cell types that are widely studied and most commonly used for cell transplantation to treat spinal cord injury, due to their intrinsic characteristics including the ability to secrete a variety of neurotrophic factors. This mini review summarizes the recent findings of endogenous Schwann cells after spinal cord injury and discusses their role in tissue repair and axonal regeneration. After spinal cord injury, numerous endogenous Schwann cells migrate into the lesion site from the nerve roots, involving in the construction of newly formed repaired tissue and axonal myelination. These invading Schwann cells also can move a long distance away from the injury site both rostrally and caudally. In addition, Schwann cells can be induced to migrate by minimal insults (such as scar ablation) within the spinal cord and integrate with astrocytes under certain circumstances. More importantly, the host Schwann cells can be induced to migrate into spinal cord by transplantation of different cell types, such as exogenous Schwann cells, olfactory ensheathing cells, and bone marrow-derived stromal stem cells. Migration of endogenous Schwann cells following spinal cord injury is a common natural phenomenon found both in animal and human, and the myelination by Schwann cells has been examined effective in signal conduction electrophysiologically. Therefore, if the inherent properties of endogenous Schwann cells could be developed and utilized, it would offer a new avenue for the restoration of injured spinal cord.     

Biphasic <Superscript>68</Superscript>Ga-PSMA-HBED-CC-PET/CT in patients with recurrent and high-risk prostate carcinoma

Purpose

Binding of ⁶⁸Ga-PSMA-HBED-CC (⁶⁸Ga-PSMA) at prostate cancer (PC) cells increases over time. A biphasic protocol may help separating benign from tumor lesions. The aim of this study was the retrospective evaluation of a diagnostic incremental value of a dual-time point (biphasic) ⁶⁸Ga-PSMA-PET/CT in patients with prostate cancer.

Methods

Retrospective analysis of 35 consecutive patients (49–78 years, median 71) with newly diagnosed PC (12/35) or recurrence of PC (23/35). PET/CT (Gemini TF16, Philips) was acquired 1 h and 3 h p. i. of 140–392 MBq (300 MBq median) ⁶⁸Ga-PSMA, followed by a diagnostic contrast CT. PET findings were correlated with histology or unequivocal CT findings. Semiquantitative PET data (SUVmax, SUV mean) were acquired and target-to-background-ratios (T/B-ratio) were calculated for benign and malign lesions for both time points. Size of lymph nodes (LN) on diagnostic CT was recorded. Statistical analysis was performed for assessment of significant changes of semiquantitative PET-parameters over time and for correlation of size and uptake of lymph nodes.

Results

One hundred and four lesions were evaluated. Sixty lesions were referenced by histology or unequivocal CT findings, including eight (13.3 %) histopathologically benign lymph nodes, 12 (20 %) histopathologically lymph node metastases, 12 (20 %) primary tumors, three (5 %) local recurrences, and 25 (41.7 %) bone metastases. Forty-four lesions were axillary LN with normal CT-appearance. Benign lesions had significantly lower SUVmax and T/B-ratios compared with malignant findings. Malign lesions showed a significant increase of both parameters over time compared to benign findings. There was no correlation between LN size and SUVmax. The sensitivity, specificity, the positive predictive value and negative predictive value of PET/CT regarding pelvic LN was 94 %, 99 %, 89 %, and 99.5 %, respectively.

Conclusions

In contrast to benign tissues, the uptake of proven tumor lesions increases on ⁶⁸Ga-PSMA-PET/CT over time. A biphasic PET-study may lead to a better detection of tumor lesions in unequivocal findings.

     

MyomiRs 在维甲酸诱导舌发育异常中对舌肌分化调控的机制研究

目的：检测维甲酸（Retinoic acid,RA）诱导小鼠胚胎腭裂模型中胎鼠舌体发育过程中肌相关 microRNAs（MyomiRs）、成肌调节因子（Myogenic regulatory factors,MRFs）以及 Pax 基因的表达变化,探究 MyomiRs 在舌肌分化过程中的调控作用,推测RA 致胎鼠腭裂伴发舌异常的可能机制。方法：建立 RA 诱导小鼠胚胎腭裂模型,分别在 E13．5、E14．5、E15．5收集胎鼠舌体组织,用 SYBR GreenⅠ实时定量 PCR 检测舌体中 MRFs 和 Pax 基因的表达;用 TaqMan 探针实时定量 PCR 检测舌体中 MyomiRs 的表达。结果：胎鼠舌体发育过程中,正常组 miR-1和 miR-206相对表达量均持续上升,RA 诱导组二者变化趋势与正常组相似,但相对表达量均低于正常组,miR-1的结果在 E14．5和 E15．5具有统计学意义（P ＜0．01）,miR-206的结果在 E13．5具有统计学意义（P ＜0．05）。正常组和 RA 诱导组胎鼠舌体中 MyoD 和 Myf5相对表达量都在 E14．5达到峰值,随后下降。RA 诱导组 MyoD 的表达在 E14．5显著低于正常组（P ＜0．05）,在 E15．5显著高于正常组（P ＜0．01）;RA 诱导组 Myf5的表达在 E15．5显著低于正常组（P ＜0．05）。正常组和 RA 诱导组胎鼠舌体中 Pax3表达均在 E14．5达到峰值,Pax7表达均在 E15．5达到峰值。RA 诱导组 Pax3的表达在 E14．5显著高于正常组（P ＜0．05）;Pax7的表达则在 E13．5显著高于正常组（P ＜0．01）。结论：在舌肌分化过程以及RA 诱导腭裂胎鼠的舌发育异常中,miR-1／miR-206与 Pax3／Pax7及 Myf5／MyoD 的表达趋势具有相关性。RA 可能通过下调 miR-1／miR-206而靶向上调 Pax3／Pax7,进而下调 MyoD ／Myf5表达,从而抑制舌肌分化,导致舌肌发育异常。