Local cerebral blood flow responses in rats to hypercapnia and hypoxia in the rostral ventrolateral medulla and in the cortex.

The effects of hypercapnia and hypoxia on two local cerebral blood flows in the parietal cortex (PC-BF) and rostral ventrolateral medulla (RVLM-BF) were examined using laser Doppler flowmetry in anesthetized rats. Hypercapnia for 45 s duration at the end-tidal CO2 between 5% and 10%, induced by increasing inspiratory CO2, increased both cerebral blood flows and systemic blood pressure in a degree-dependent manner. The response of RVLM-BF was significantly stronger than that of PC-BF. Both cerebral blood flow responses to hypercapnia were not influenced by cutting peripheral chemoreceptor afferent nerves. Hypoxia for 45 s duration at the end-tidal O2 between 12% and 6%, induced by decreasing inspiratory O2, produced an increase of similar magnitude in both RVLM and PC local blood flows in a degree-dependent manner and a decrease in systemic blood pressure. The responses of both PC-BF and RVLM-BF to hypoxia were significantly diminished after cutting peripheral chemoreceptor afferent nerves. It is concluded that: (1) the RVLM-BF is much more sensitive to hypercapnia than the PC-BF; and (2) activation of peripheral arterial chemoreceptors possibly contributes to hypoxia-induced increase in the RVLM-BF and PC-BF.     

Survival following hydrofluoric acid ingestion.

Systemic toxicity after significant dermal exposure to hydrofluoric acid includes rapid development of hypocalcemia and hyperkalemia, leading to ventricular fibrillation. Similar dysrhythmias have occurred in patients after ingestion of sodium fluoride-containing compounds. Ingestion of hydrofluoric acid could induce similar cardiac toxicity; however, reported cases of hydrofluoric acid ingestion rarely have been described, and the rapid death of these patients has not allowed verification of this hypothesis. On two separate occasions, a 70-year-old woman ingested up to 2 oz of a 8% hydrofluoric acid-containing solution. Recurrent ventricular fibrillation with concurrent hypocalcemia and hypomagnesemia complicated her first episode, whereas a more aggressive administration of calcium and magnesium may have prevented dysrhythmias in the second episode. Survival from ventricular fibrillation after hydrofluoric acid ingestion has not been reported previously and suggests a role for aggressive empiric calcium and magnesium replacement.     

The Influence of Intramammary Lipopolysaccharide Infusion on Serum Ca,P, Vitamin D,Cytokines and Cortisol Concentrations in Lactating Sows

Ten multiparous lactating sows were used to investigate whether intramammary infusion of lipopolysaccharides (LPS; Escherichia coli 0111:B4; 2.0 μg/kg of body weight) would affect the circulating concentrations of Ca, P, 25‐hydroxyvitamin D (25‐OHD), tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and cortisol. The sows were randomly allotted to either control group (control) or LPS‐treated group with five individuals per group and were infused with either physiological saline solution or LPS solution. The rectal temperature and udder quarter appearance were recorded at 0 (just before infusion), 1, 3, 7, 12 or 24 h after infusion. Blood samples were taken at 0, 1, 3, 7, 12 or 24 h after infusion. Before infusion, the rectal temperatures of all sows were below 39.2°C. At 3 and 7 h after infusion, the sows in the LPS group had a rectal temperature over 39.4°C. At 24 h after infusion, the rectal temperatures returned to pre‐infusion levels. Serum Ca and P concentrations in the LPS group decreased (P < 0.05) after LPS infusion compared with the control group at 1 h after infusion. No significant differences (P > 0.05) in the concentrations of 25‐OHD were observed between groups control and LPS at any sampling time. Increased (P < 0.01) concentrations of serum TNF‐α, IL‐6 and cortisol were observed in the LPS group compared with the control group at 3 and 7 h after infusion respectively. In conclusion, the elevation of serum concentrations of TNF‐α, IL‐6 and cortisol and the alterations of circulating concentrations of Ca and P following LPS infusion indicate that the immune system has been activated and immune activation may affect macromineral homeostatic regulation, which might have important implications for metabolic health of lactating sows. Lowered serum Ca and P following immune activation also shows a causative mechanism whereby immune activation increases the risk of secondary disorders such as mastitis‐metritis‐agalactia syndrome. However, immune activation did not affect circulating concentrations of vitamin D metabolites.     

帕金森病立体定向手术并发脑内出血的原因分析

目的:探讨帕金森病立体定向手术颅内出血并发症原因及对策。方法:自1999年4月至2003年3月我们对药物治疗效果不理想的510例帕金森病病人行立体定向毁损手术，术后出现颅内出血9例，其中毁损灶出血3例，穿刺道出血6例。结果:手术治疗4例．保守治疗5例。术后意识恢复但遗留偏瘫4例，经非手术治疗5例．恢复良好，未遗留明显功能障碍。全组无死亡病例。结论:采用磁共振结合微电极导向提高靶点定位精确度，减少微电极记录针道数，降低毁损温度，重视围手术期处理等措施，有助于降低颅内出血并发症的危险。     

Soluble polystyrene derivatives of metal bis(3,4-dicarboxybenzoyl)phthalocyaninates: Synthesis,thermal analysis,and sensitivity towards toxic gases

Polystyrene-bound metal [2,9 or 2,10 (or 2,16 or 2,17) bis(3,4-dicarboxybenzoyl)]phthalocyaninates were synthesized by Friedel-Crafts reaction of polystyrene with the corresponding metal phthalocyaninates. Co(II) and Cu(II) [2,9 or 2,10 (or 2,16 or 2,17) bis(3,4-dicarboxybenzoyl)]-phthalocyaninate (PS-CodaPc and PS-CudaPc) contained 0,13 mmol · g^?1 (12,4 wt.-%) and 0,13 mmol · g^?1 (12,8 wt.-%) of CodaPc and CudaPc, respectively. They were soluble in N,N'-dimethylformamide, but only partially soluble in chloroform, tetrahydrofuran (THF), dimethyl sulfoxide, N-methyl-2-pyrrolidone, and pyridine. The THF extracts contained 0,12 mmol · g^?1 (11,4 wt.-%) and 0,18 mmol ? g^?1 (17,2 wt.-%) of PS-CodaPc and PS-CudaPc, respectively. The thermal stability of the polymers was studied using thermogravimetric and differential thermal analysis in nitrogen and synthetic air atmosphere. The contents of MdaPc(M: metal) in THF-extracted polymers calculated from the data of residue in thermogravimetric analysis are 0,12 mmol · g^?1 for PS-CodaPc and 0,19 mmol · g^?1 for PS-CudaPc. In addition, the sensitive properties of the polymers towards toxic gases were also investigated by quartz microbalance transducers. The results show that the quartz microbalance sensors coated with both polymers were sensitive to NO₂ and chlorinated hydrocarbons, i.e. chloroform and perchloroethylene. The sensitivity to NO₂ was 6,53 · 10^?7 m³ · mL^?1 · s^?1 for PS-CodaPc and 1,90 · 10^?6 m³ · mL^?1 · s^?1 for PS-CudaPc, and that to chloroform and perchloroethylene was 2,33 · 10^?8 and 4,60 · 10^?8 m³ · mL^?1 · s^?1, respectively, for PS-CodaPc and 4,79 · 10^?8 and 9,51 · 10^?7 m³ · mL^?1 · s^?1 for PS-CudaPc.     

甾体避孕药不增加血栓栓塞性疾病危险(病例对照研究)

本文采用1:3病例对照研究方法,对甾体避孕药的使用与血栓栓塞性疾病(急性心肌梗塞、脑栓塞、脑血栓形成和深静脉血栓形成)间的关联进行多因素分析。结果提示在我国广泛应用的甾体避孕药(主要为国产Ⅰ号避孕药)并不增加血栓栓塞性疾病的危险性。用药和停药时间的长短与血栓栓塞性疾病的发生无关,并与高血压病之间亦不存在协同作用。     

The adverse effect of treatment prolongation in cervical cancer by high-dose-rate intracavitary brachytherapy.

BACKGROUND AND PURPOSE: The potential risk of prolongation of treatment time in cervical cancer has been reported for many low-dose rate (LDR) studies, with an estimated loss of local control ranging from 0.3 to 1.6% per day of treatment prolongation. Since the treatment schedule for fractionated high-dose rate intracavitary brachytherapy (HDRICB) is not directly comparable with that for low-dose rate studies, this report aims to evaluate the adverse effect of treatment prolongation specifically for cervical cancer treated with HDRICB. MATERIAL AND METHODS: From September 1992 to December 1997, 257 patients diagnosed with uterine cervical cancer (35 Ib, 26 IIa, 122 IIb, 10 IIIa, 57 IIIb, 7 IVa), who underwent external radiotherapy combined with between two and four courses of HDRICB and a minimum of 3 years of follow-up (median 57 months), were analyzed. Treatment consisted of irradiation of the whole pelvis with 44-45 Gy consisting of 22-25 fractions by 5 weeks, with the dose boosted to 54-58 Gy (with central shielding) for patients diagnosed as FIGO stage IIb-IVa bilateral parametrial disease. HDRICB was performed using an Ir-192 remote afterloading technique at 1-week intervals. The standard prescribed dose for each course of HDRICB was 7.2 Gy to point A for three insertions (before July 1995), or 6.0 Gy to point A for four insertions (after July 1995). Total prescribed point A doses (external beam radiotherapy+HDRICB) ranged from 58 to 71.6 Gy (median, 65.6 Gy) for stage IB-IIA, while analogous dosage for larger lesions (stage IIb-IVa) ranged from 59 to 75.6 Gy (median, 65.6 Gy). Kaplan-Meier and multivariate analyses were used to test the effect of treatment time on pelvic control rate (PCR) and cause-specific survival (CSS) at 5 years. RESULTS: Median treatment time was 63 days. For all stages of disease, the 5-year CSS and PCR were significantly different comparing treatment times of less than and greater than or equal to 63 days [83% and 65% (P=0.004], 93% and 83% (P=0.02), respectively]. These associations were also significant for stage Ib/IIa [97% and 79% (P=0.01), and 100% and 87% (P=0.02), respectively), but not for stage IIb [75% and 72% (P=0.79), and 93% and 87% (P=0.83), respectively] or stage III [66% and 49% (P=0.2), and 83% and 72% (P=0.21), respectively]. Multivariate analysis identified three prognostic factors for CSS, stage (P<0.001), tumor response to external RT (P=0.001), and overall treatment time (OTT; P=0.006). Prognostic factors for pelvic failure were stage (P<0.001), tumor response to external RT (P=0.001), and OTT (P=0.03). Prolongation of treatment time resulted in a daily decrease in pelvic control rate of 0.67% overall, and 0.43% for stage Ib-IIa, 0.57% for stage IIb, and 0.73% for stage III patients. CONCLUSION: Analysis of the data from the current study demonstrates that the adverse effect of treatment prolongation was observed later in the treatment course for the high-dose rate (HDR) series compared to the LDR analog, however, treatment-time prolongation still negatively influenced the cause-specific survival and pelvic control rate for both dosage groups.     

A Bayesian iterative transmission gradient reconstruction algorithm for cardiac SPECT attenuation correction

Background  High-quality attenuation maps are critical for attenuation correction of myocardial perfusion single photon emission computed tomography studies. The filtered backprojection (FBP) approach can introduce errors, especially with low-count transmission data. We present a new method for attenuation map reconstruction and examine its performance in phantom and patient data. Methods and Results  The Bayesian iterative transmission gradient algorithm incorporates a spatially varying gamma prior function that preferentially weights estimated attenuation coefficients toward the soft-tissue value while allowing data-driven solutions for lung and bone regions. The performance with attenuation-corrected technetium 99m sestamibi clinical images was evaluated in phantom studies and in 50 low-likelihood patients grouped by body mass index (BMI). The algorithm converged in 15 iterations in the phantom studies. For the clinical studies, soft-tissue estimates had significantly greater uniformity of mediastinal coefficients (mean SD, 0.005 cm⁻¹ vs 0.011 cm⁻¹; P<.0001). The accuracy and uniformity of the Bayesian iterative transmission gradient algorithm were independent of BMI, whereas both declined at higher BMI values with FBP. Attenuation-corrected perfusion images showed improvement in myocardial wall variability (4.8% to 4.1%, P=.02) for all BMI groups with the new method compared with FBP. Conclusion  This new method for attenuation map reconstruction provides rapidly converging and accurate attenuation maps over a wide spectrum of patient BMI values and significantly improves attenuation-corrected perfusion images.