SSF改善小鼠化学性记忆障碍的作用观察

目的：研究SSF对基些化学试剂引起小鼠学习记忆障碍的作用。方法：采用小鼠水迷宫行为实验法，检测SSF对东莨菪碱、戊巴比妥钠引起小鼠学习、记忆障碍的作用。小鼠到达终点平台时间（潜伏期）和进入盲端次数作为检测指标，脑复康为对照药。结果：单次腹腔注射东莨菪碱3mg/kg明显损害已训练达标小鼠记忆，灌胃50、100、200mg/kgSSF明显逆转东莨菪碱产生小鼠记忆障碍。在连续5天记忆获得实验中，15mg/kg戊巴比妥钠明显抑制小鼠记忆获得，200mg/kg脑富康(ig,12d)和50、100、200mg/kg（灌胃，12d)SSF皆能显著降低戊巴比妥钠引起小鼠到达终点平台的潜伏期和进入盲端的次数。结论：SSF能够改善戊巴比妥钠东莨菪碱和产生的小鼠记忆障碍。     

Renal allografts: prospective analysis of Doppler sonography

Fifty-six consecutively transplanted renal allografts were prospectively evaluated with serial Doppler sonographic examinations. Thirty-eight episodes of transplant rejection in 32 patients (63% proved pathologically) and 24 episodes of acute tubular necrosis (ATN) in 24 patients were encountered. The Doppler spectral waveform was characterized by means of the pulsatility index (PI), systolic/diastolic ratio (SDR), diastolic/systolic ratio (SDR), diastolic/systolic ratio (DSR), and resistive index (RI). Accuracy was optimized with use of top normal values as follows: PI = 1.8, SDR = 4.0, DSR = 0.25, RI = 0.75. There were no significant differences in the indices for those patients undergoing rejection versus those with ATN. The sensitivity for predicting transplant rejection was adversely affected by the history of either ATN or a previous rejection episode in the same allograft. Comparison with concurrent radionuclide examinations revealed similar sensitivities for rejection with scintigraphy and sonography. Differentiation of ATN from rejection was more reliable with scintigraphy than with sonography.     

Lamotrigine versus placebo in the prophylaxis of migraine with and without aura

Lamotrigine blocks voltage-sensitive sodium channels, leading to inhibition of neuronal release of glutamate. Release of glutamate may be essential in the propagation of spreading cortical depression, which some believe is central to the genesis of migraine attacks. This study compared safety and efficacy of lamotrigine and placebo in migraine prophylaxis in a double-blind randomized parallel-groups trial. A total of 110 patients entered; after a 1-month placebo run-in period, placebo-responders and non-compliers were excluded, leaving 77 to be treated with lamotrigine ( n =37) or placebo ( n =40) for up to 3 months. Initially lamotrigine therapy was commenced at the full dose of 200 mg/day, but, following a high incidence of skin rashes, a slow dose-escalation was introduced: 25 mg/day for 2 weeks, 50 mg/day for 2 weeks, then 200 mg/day. Attack rates were reduced from baseline means of 3.6 per month on lamotrigine and 4.4 on placebo to 3.2 and 3.0 respectively during the last month of treatment. Improvements were greater on placebo and these changes, not statistically significant, indicate that lamotrigine is ineffective for migraine prophylaxis. There were more adverse events on lamotrigine than on placebo, most commonly rash. With slow dose-escalation their frequency was reduced and the rate of withdrawal for adverse events was similar in both treatment groups.     

Normal variation in the frequency and location of human auditory cortex landmarks. Heschl's gyrus: where is it?

Interpersonal communication via the auditory modality is fundamental to normal human development. One of the prominent anatomical specializations supporting this communication is the transverse gyrus of Heschl on the superior surface of the temporal lobe. This gyrus frequently appears duplicated, either by a sulcus indenting the crown of an initially single gyrus (common stem), or by a complete posterior duplication. The frequency of these duplications has been reported to be elevated in populations with learning disabilities and genetic anomalies. The significance of this observation is unclear, however, due to conflicting reports of the base rate of duplication and the location of relevant sulcal landmarks. In this study we report the variation in frequency and location of the sulcal boundaries of Heschl's gyrus in volumetric magnetic resonance imaging scans of 105 normal controls aged 5-65. The major results were as follows: (i) duplications were unstable--the frequency of duplication ranged from 20 to 60% depending on distance from the midline; (ii) common stem duplications were more frequent than posterior duplications, particularly in the right hemisphere. Intra- and interindividual instability in sulcal landmarks pose serious obstacles to the attempt to map behavioral function onto the brain. Novel methods for dealing with structural variation are needed to facilitate the development of valid mapping techniques.      

Catabolism in critical illness: estimation from urea nitrogen appearance and creatinine production during continuous renal replacement therapy

Thirty-eight intensive care unit (ICU) patients (26 men and 12 women with a mean age of 57.0 +/- 16.6 years) with acute renal failure (ARF) treated by venovenous continuous renal replacement therapy (CRRT) were evaluated while in relatively steady metabolic control. Twenty-seven were undergoing continuous venovenous hemodialysis, nine were undergoing continuous venovenous hemodiafiltration, and two were undergoing continuous venovenous hemofiltration. Periods of analysis varied between 24 and 408 hours (mean duration, 82.7 +/- 70.6 hours; median, 72 hours). Their mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score within 24 hours of admission to the ICU was 21.3 +/- 6.3 and survival rate was 31.6%. Urea nitrogen and creatinine concentrations were determined every 6 to 12 hours in both serum (Cun and Cc, respectively) and effluent (spent dialysate and/or ultrafiltrate). The mean effluent rate was 1,472 +/- 580 mL/h and blood flow rate, 166 +/- 32 mL/min. Urine was collected daily for urea nitrogen and creatinine measurement. Urea nitrogen appearance rate (UnA) and creatinine production rate (Pc), calculated from urea nitrogen (UnMR) and creatinine mass removal (CMR) from both the effluent and the urine, using Garred mass balance equations and the Forbes-Bruining formula, allowed normalized protein catabolic rate (nPCR) and estimates of lean body mass (LBM) to be derived. Creatinine metabolic degradation rate (Dc), estimated by the Mitch formula, was included in the calculation. The lowest body weight recorded during the study period was considered as dry weight (BW). The creatinine index (CI) was also obtained. For each parameter, the results are presented as mean, median, and range values: UnMRe (from effluent), 13.6 +/- 7.2, 12.5, 1.6 to 32.6 mg/min; UnMRu (from urine), 0.13 +/- 0.40, 0, 0 to 2.30 mg/min; UnA, 13.6 +/- 7.0, 12.5, 3.8 to 32.1 mg/min; nPCR, 1.75 +/- 0.82, 1.60, 0.61 to 4.23 g/kg/d; CMRe (from effluent), 942.0 +/- 362.3, 918.0, 211.2 to 1,641.6 mg/d; CMRu (from urine), 44.4 +/- 138.8, 0, 0 to 698.5 mg/d; Dc, 94.6 +/- 49.9, 81.9, 31.0 to 294.1 mg/d; Pc total, 1,067.1 +/- 409.7, 1,053.7, 261.5 to 1,988.2 mg/d; LBM, 38.3 +/- 11.9, 37.9, 15.0 to 65.0 kg; LBM/BW ratio, 49.5% +/- 14.0%, 50.3%, 22.5% to 86.0%; and CI, 13.7 +/- 4.7, 14.2, 4.1 to 25.8 mg/kg/d. When Pc was estimated from the Cockcroft-Gault equations (as Pc'), the mean value for Pc and Pc' was similar (1,067.1 +/- 409.7 v 1,284.9 +/- 484.1 mg/d), but there were relatively large differences for the majority of cases. A positive correlation was observed between UnA and Pc (R = 0.42). Serum albumin and LBM/BW correlated poorly (R = 0.20). Outcome was weakly related to UnA and to nPCR (R = 0.29 and R = 0.31, respectively). Urea nitrogen appearance appears widely variable in critically ill ARF patients. This simple approach can provide useful information for an easy estimate of net protein catabolism in critically ill patients with ARF undergoing CRRT.     

Wilms tumor occurring as a botryoid renal pelvicalyceal mass

Wilms tumor usually occurs as an abdominal mass arising from the renal parenchyma. A case was encountered in which the neoplasm filled the pelvicalyceal system of an 8-year-old boy as a botryoid mass, with minimal parenchymal involvement. The radiologic manifestations, pathologic features, and surgical implications are discussed.     

The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics

Bacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. The primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. This can only be achieved through the use of a combination of aseptic treatment techniques, chemomechanical preparation of the root canal, antimicrobial irrigating solutions and intracanal medicaments. The choice of which intracanal medicament to use is dependent on having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organisms likely to be involved and their mechanisms of growth and survival. Since the disease is likely to have been caused by the presence of bacteria within the root canal, the use of an antimicrobial agent is essential. Many medicaments have been used in an attempt to achieve the above aims but no single preparation has been found to be completely predictable or effective. Commonly used medicaments include calcium hydroxide, antibiotics, non-phenolic biocides, phenolic biocides and iodine compounds. Each has advantages and disadvantages, and further research is required to determine which is best suited for root canal infections.