Behavioral and neurophysiological effects of delayed training following a small ischemic infarct in primary motor cortex of squirrel monkeys

A focal injury within the cerebral cortex results in functional reorganization within the spared cortex through time-dependent metabolic and physiological reactions. Physiological changes are also associated with specific post-injury behavioral experiences. Knowing how these factors interact can be beneficial in planning rehabilitative intervention after a stroke. The purpose of this study was to assess the functional impact of delaying the rehabilitative behavioral experience upon movement representations within the primary motor cortex (M1) in an established nonhuman primate, ischemic infarct model. Five adult squirrel monkeys were trained on a motor-skill task prior to and 1 month after an experimental ischemic infarct was induced in M1. Movement representations of the hand were derived within M1 using standard electrophysiological procedures prior to the infarct and again one and two months after the infarct. The results of this study show that even though recovery of motor skills was similar to that of a previous study in squirrel monkeys after early training, unlike early training, delayed training did not result in maintenance of the spared hand representation within the M1 peri-infarct hand area. Instead, delaying training resulted in a large decrease in spared hand representation during the spontaneous recovery period that persisted following the delayed training. In addition, delayed training resulted in an increase of simultaneously evoked movements that are typically independent. These results indicate that post-injury behavioral experience, such as motor skill training, may modulate peri-infarct cortical plasticity in different ways in the acute versus chronic stages following stroke.     

In vivo dosimetry by an aSi-based EPID

A method for the in vivo determination of the isocenter dose, Diso, and mid-plane dose, Dm, using the transmitted signal St measured by 25 central pixels of an aSi-based EPID is here reported. The method has been applied to check the conformal radiotherapy of pelvic tumors and supplies accurate in vivo dosimetry avoiding many of the disadvantages associated with the use of two diode detectors (at the entrance and exit of the patient) as their periodic recalibration and their positioning. Irradiating water-equivalent phantoms of different thicknesses, a set of correlation functions F(w, l) were obtained by the ratio between St and Dm as a function of the phantom thickness, w, for a different field width, l. For the in vivo determination of Diso and Dm values, the water-equivalent thickness of the patients (along the beam central axis) was evaluated by means of the treatment planning system that uses CT scans calibrated in terms of the electron densities. The Diso and Dm values experimentally determined were compared with the stated doses D(iso,TPS) and D(m,TPS), determined by the treatment planning system for ten pelvic treatments. In particular, for each treatment four fields were checked in six fractions. In these conditions the agreement between the in vivo dosimetry and stated doses at the isocenter point were within 3%. Comparing the 480 dose values obtained in this work with those obtained for 30 patients tested with a similar method, which made use of a small ion-chamber positioned on the EPIDs to obtain the transmitted signal, a similar agreement was observed. The method here proposed is very practical and can be applied in every treatment fraction, supplying useful information about eventual patient dose variations due to the incorrect application of the quality assurance program based on the check of patient setup, machine setting, and calculations.     

绿色荧光染料SYTO 16在脑肿瘤细胞流式细胞分析中的应用

背景与目的：确定肿瘤细胞DNA的含量在恶性肿瘤的恶性程度分级诊断中很重要。本研究比较SYTO16与碘化丙啶（PI）两种染料的异同．旨在找到一种适合于在脑肿瘤活细胞中检测DNA含量的染料,研究使用SYTO16染色后用流式细胞仪分选出的活细胞不同周期细胞的特性。方法：用FACSCalibar流式细胞仪测定DNA含量。用FACS Vantage SE流式细胞仪根据不同的细胞周期分选细胞。免疫组化染色。结果：SYTO16能用于DNA含量的测定,但测定的结果与PI测定的结果不同,测定的GdG,期的比例高于PI测定的结果,（P〈0．05）。SYTO16能用于活细胞的DNA含量的测定,测定活细胞的结果与固定后细胞的结果比较,二者无显著性差异（P〉0．05）。两种荧光是不同的．通过不同时相的观察还可以看出SYTO染色后的细胞其荧光消失较快。结论：SYTO16可以用于脑胶质瘤细胞DNA含量的测定并且可用于活细胞。如果染色后稳定性及线粒体、细胞粘连等方面的影响能避免的话．可用于细胞的分选。     

Combined-modality therapy in locally advanced primary rectal cancer

PURPOSE: Patients with unresectable, locally advanced rectal cancer are reported to have a dismal prognosis. The aim of this study was to analyze the effect of combined-modality therapy on clinical outcome. METHODS: From March 1990 to December 1997, 43 patients (28 males; median age, 62 years; median follow-up, 74 months) with locally advanced (T4 and/or N3) nonmetastatic rectal cancer received external-beam radiation (23.6 plus 23.6 Gy (split course), 8 patients; 45 Gy, 35 patients) plus 5-fluorouracil (96-hour continuous infusion, Days 1–4, at 1,000 mg/m2/day) and mitomycin C (10 mg/m2, intravenous bolus, Day 1). Concomitant chemotherapy was repeated at the beginning of the second course (split-course group) or in the last week of radiotherapy (continuous-course group). After 6 to 8 weeks, patients were evaluated for surgical resection and intraoperative radiation therapy (10 to 15 Gy). Thereafter, adjuvant chemotherapy (5-fluorouracil plus leucovorin, 6–9 courses) was prescribed. RESULTS: During chemoradiation, 5 patients (11.6 percent) developed Grade 3 to 4 hematologic toxicity. After chemoradiation, 29 patients (67.4 percent) had an objective clinical response (complete response, 2.3 percent; partial response, 65.1 percent). Thirty-eight patients underwent radical surgery (anterior resection, 24 patients; abdominoperineal resection, 14 patients; intraoperative radiation therapy boost on the tumor bed, 19 patients), and 2 patients had partial tumor resection. No perioperative deaths occurred in the patient group. Five-year survival and local control rates were 59.9 and 69.1 percent, respectively. Distant metastasis occurred in 44.2 percent of patients. Statistically significant relationships between intraoperative radiation therapy and local control (P = 0.0104), radical surgery and survival (P = 0.0120), and adjuvant chemotherapy and disease-free survival (P = 0.0112) were observed. CONCLUSIONS: Our data suggest that combined-modality therapy was relatively well tolerated and resulted in good local control and survival. With regard to the impact of surgical resection on survival, additional studies aimed at improving the local response rate are necessary, whereas the positive impact of intraoperative radiotherapy on local control appears to justify the inclusion of this therapeutic modality in prospective multi-institutional trials.     

Comparative study of five preoperative methods for the localization of accessory pathways in the Wolff-Parkinson-White syndrome

One hundred and thirty-four cases of Wolff-Parkinson-White syndrome were studied to evaluate the relative usefulness of electrocardiography (ECG), electrophysiological studies (EPS), body surface mapping (BSM), gated blood-pool phase analysis (nuclear studies), and vectorcardiography (VCG) in the localization of the accessory pathway (ACP). In comparison with the final localization verified by intraoperative studies, 93.4% in 8-region ACP localization (97.7% in 4-region ACP localization) could be correctly localized by ECG using our criteria, 83.9% (86.8%) by EPS, 82.6% (95.8%) by BSM, 78.8% (87.7%) by nuclear studies, and 67.3% (78.0%) by VCG. It was concluded that: (a) ACP can be localized preoperatively with considerable accuracy by using our simple ECG criteria. (b) The EPS method has some limitation, especially with respect to 8-region ACP localization. (c) Our observation showed no evidence that BSM, VCG, or nuclear studies were superior to ECG in ACP localization. (d) Among the 5 methods studied, ECG and EPS appear to be the appropriate procedures for preoperative ACP identification.     

Comparison of intraocular penetration level of cefuzonam sodium and cefotiam after intravenous and subconjunctival injection

We investigated the intraocular penetration of a new Cephem type antibiotic: Cefuzonam sodium (CZON) following intravenous and subconjunctival injection. CZON was administered to 28 eyes in 26 patients by 1 g intravenous injection (IV) and to 11 eyes in 10 patients by 20 mg/0.2 ml subconjunctival injection (SCI). The penetration level of CZON by the IV method was from less than 0.0025-3.35 micrograms/ml into aqueous humor, from less than 0.0025-0.315 microgram/mg into iris tissue and 2.7-157.5 micrograms/ml into serum. The penetration level of CZON by the SCI method was from less than 0.0025-12.8 micrograms/ml into aqueous humor, from less than 0.0025-0.0426 microgram/mg into iris tissue and 1.03-18.5 micrograms/ml into serum. The penetration level of CZON into aqueous humor by SCI was higher than by IV administration. In comparison with the penetration level of CZON and Cefotiam (CTM), both aqueous humor and serum levels of CTM were higher than those of CZON. These results suggested that therapeutic levels in aqueous humor effective against gram-positive and gram-negative pathogens were achieved with the 1 g IV and 20 mg SCI of CZON. However levels effective against Staphylococcus epidermidis were only erratically attained.     

Concomitant preoperative radiochemotherapy in operable locally advanced rectal cancer

PURPOSE: The aim of this study was to examine the effectiveness of a combination of preoperative radiotherapy and chemotherapy for operable locally advanced rectal cancer (Stages II and III). METHODS: Chemotherapy and radiotherapy are started jointly on day one of the therapy. 5-Fluorouracil is given in a dosage of 1000 mg/ m²/day as a continuous 24-hour infusion for 4 days. Mitomycin C is given as a bolus intravenous at a dosage of 10 mg/m² the first day. The radiation therapy is given to a total dosage of 37.8 Gy. Surgery is generally performed four to five weeks following completion of the radiation therapy. From March 1990 to April 1993, 34 patients with histologically documented adenocarcinoma of the rectum have been treated. Twenty-one lesions were located in the lower third of the rectum. Twenty-nine neoplasms were judged by initial clinical staging as Stage III. RESULTS: Patients compliance to the treatment have been 97 percent. Toxicity of treatment has been low (15 percent). Tumor sizes decreased 50 percent or more in about 80 percent of patients. Distance of the tumor from the anal canal increased in all but seven cases. Twenty-two anterior resections have been performed. The morbidity rate has been 24 percent. No postoperative mortality has been reported. Histologic examination of surgical specimens after integrated treatment showed in 10 cases a tumor confined to the rectal wall (T2), in 3 patients only a residual tumor limited to submucosa (T1), and in 5 (15 percent) patients no evidence of neoplastic cells (T0). CONCLUSIONS: We conclude that preoperative radiochemotherapy was generally well tolerated; in all cases we had a reduction of tumor sizes, surgery presented no technical difficulties, and there was the effect of stage reduction.     

Clinical significance of measurement of plasma melatonin concentration in women with irregular menstrual cycles

To study the effects of melatonin on the human hypophyseal ovarian axis, we measured the concentrations of melatonin in the plasma of women with a regular menstrual cycle and of women with an abnormal menstrual cycle, at days 5 through 10 after the onset of menstruation or withdrawal bleeding. In seven women with a regular menstrual cycle, there was a tendency for the plasma melatonin concentration to gradually decrease chronologically from 49.0 +/- 9.8pg/ml (M +/- S.E.) at 9:30 h to 19.0 +/- 4.0pg/ml at 12:00 h. On the other hand, the plasma melatonin concentration at 21:30 h was 50.3 +/- 7.4pg/ml which was almost the same as the level at 9:30 h, while the concentration during the night significantly increased chronologically to 106.3 +/- 28.6pg/ml at 24:00 h. By comparing the plasma melatonin concentration measured during the day with that measured during the night, a significant difference was discovered after 21:40 h (p less than 0.05). The plasma melatonin concentration at 10:00 h and 22:00 h in 20 women with a regular menstrual cycle was 28.1 +/- 3.4pg/ml and 72.2 +/- 9.9pg/ml, respectively, showing a diurnal rhythm with a significantly higher level during the night than during the day. On the other hand, the plasma melatonin concentration in most of the women with an anovulatory cycle or amenorrhea was within the range of the mean level of +/- 1.5 x the standard deviation obtained from the 20 women with a regular menstrual cycle. However, an increase in plasma melatonin during the night was not found in three of nine women with an anovulatory cycle and one of two women with second grade amenorrhea.(ABSTRACT TRUNCATED AT 250 WORDS)