Chromogenic ionophore-based methods for spectrophotometric assay of sodium and potassium in serum and plasma

We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high sensitivity and selectivity (negligible responses to sodium at 80 to 200 mmol/L in the potassium assay and to potassium at 0 to 10 mmol/L in the sodium assay). The within-run imprecisions are comparable with those for ion-selective electrodes (for K, 1.0% at 4.5 mmol/L; for Na, 1.1% at 136 mmol/L); the analytical range is 2-10 mmol/L for potassium, 80-170 mmol/L for sodium. The results for greater than 100 patients' samples correlated well with results obtained with ion-selective electrodes (r = 0.99 for K, 0.97 for Na). The ready-to-use aqueous reagents will be available under the trade name of ChromoLyte for use with Technicon's RA family of clinical analyzers.     

Functional MR of the primary auditory cortex: an analysis of pure tone activation and tone discrimination.

PURPOSETo use functional MR imaging to measure the effect of frequency (pitch), intensity (loudness), and complexity of auditory stimuli on activation in the primary and secondary auditory cortexes.METHODSMultiplanar echo-planar images were acquired in healthy subjects with normal hearing to whom auditory stimuli were presented intermittently. Functional images were processed from the echo-planar images with conventional postprocessing methods. The stimuli included pure tones with a single frequency and intensity, pure tones with the frequency stepped between 1,000, 2,000, 3,000, or 4,000 Hz, and spoken text. The pixels activated by each task in the transverse temporal gyrus (TTG) and the auditory association areas were tabulated.RESULTSThe pure tone task activated the TTG. The 1,000-Hz tone activated significantly more pixels in the TTG than did the 4,000-Hz tone. The 4,000-Hz tone activated pixels primarily in the medial TTG, whereas the 1,000-Hz tone activated more pixels in the lateral TTG. Higher intensity tones activated significantly more pixels than did lower intensity tones at the same frequency. The stepped tones activated more pixels than the pure tones, but the difference was not significant. The text task produced significantly more activation than did the pure tones in the TTG and in the auditory association areas. The more complex tasks (stepped tones and listening to text) tended to activate more pixels in the left hemisphere than in the right, whereas the simpler tasks activated similar numbers of pixels in each hemisphere.CONCLUSIONAuditory stimuli activate the TTG and the association areas. Activation in the primary auditory cortex depends on frequency, intensity, and complexity of the auditory stimulus. Activation of the auditory association areas requires more complex auditory stimuli, such as the stepped tone task or text reading.     

Thermodynamic stability of wild-type and mutant p53 core domain

Some 50% of human cancers are associated with mutations in the core domain of the tumor suppressor p53. Many mutations are thought just to destabilize the protein. To assess this and the possibility of rescue, we have set up a system to analyze the stability of the core domain and its mutants. The use of differential scanning calorimetry or spectroscopy to measure its melting temperature leads to irreversible denaturation and aggregation and so is useful as only a qualitative guide to stability. There are excellent two-state denaturation curves on the addition of urea that may be analyzed quantitatively. One Zn²⁺ ion remains tightly bound in the holo-form of p53 throughout the denaturation curve. The stability of wild type is 6.0 kcal (1 kcal = 4.18 kJ)/mol at 25°C and 9.8 kcal/mol at 10°C. The oncogenic mutants R175H, C242S, R248Q, R249S, and R273H are destabilized by 3.0, 2.9, 1.9, 1.9, and 0.4 kcal/mol, respectively. Under certain denaturing conditions, the wild-type domain forms an aggregate that is relatively highly fluorescent at 340 nm on excitation at 280 nm. The destabilized mutants give this fluorescence under milder denaturation conditions.     

慢性缺氧大鼠肺组织钙调素活性研究

为探讨钙调素在慢性缺氧性肺动脉高压发病中的作用，将４０只Ｗｉｓｔａｒ大鼠随机分为四组，Ｉ组为正常对照组，不接受任何处理。Ⅱ、Ⅲ、Ⅳ组为实验组，分别间断缺氧１、２、３周，而后采用火焰原子吸收分光光度法及磷酸二酯酶法测定四组大鼠肺组织Ｃａ＾２＋含量及ＣａＭ活性。     

Case Control Study of Chronic Bronchitis in glass Bangle Workers

Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India     

Management of sphenoid sinus cerebrospinal fluid rhinorrhea: making use of an extended approach to the sphenoid sinus.

OBJECTIVES: Specific information addressing the management of cerebrospinal fluid (CSF) fistulas that originate from within the sphenoid sinus remains scant. The objective of this study was to review the cause and management of CSF rhinorrhea arising from the sphenoid sinus. STUDY DESIGN AND SETTING: This is a retrospective chart review of 12 cases of CSF rhinorrhea arising from the sphenoid sinus that occurred in 11 patients. All patients were treated at a single institution between 1994 and 1999. RESULTS: All patients were managed surgically with sphenoid sinus fat obliteration using an endoscopic sublabial, transseptal approach. This approach was successful for all 12 cases, with median duration of follow-up of 18 months. CONCLUSIONS: Endoscopically assisted transseptal repair of CSF fistulas that originate within the sphenoid sinus offers an alternate approach to previously described methods of repair in this region. Advantages include wide access to the entire sphenoid sinus, improved access to laterally pneumatized regions within the sphenoid sinus, and rostral mucosal closure over the repair within the sinus.     

Surgical management of bile duct injuries following laparoscopic cholecystectomy: analysis and follow-up of 28 cases

BACKGROUND: Biliary tract lesions pose a dreaded complication of laparoscopic cholecystectomy. In a retrospective study we analyzed the clinical presentation, diagnostic and therapeutic management and outcome of 28 patients presenting with iatrogenic bile duct injuries. PATIENTS AND METHODS: Between 1994 and 2001 we treated 28 patients with bile duct lesions following laparoscopic cholecystectomy at our center. Operation notes and charts of all patients were reviewed systematically. A follow-up examination of each patient was performed after a median of 12 months (range 1-90). RESULTS: Twenty-two patients presented with major circumferential bile duct defect lesions. Less severe injuries (n=6) were two minor bile leaks, one bile duct stricture and three tangential lesions. Twenty-six patients were referred to our institution within 16 days (range 0-226 days). Six patients were treated by nonsurgical procedures: endoscopic stenting in four and percutaneous intervention in two. In one of the remaining patients a cystic duct leak was closed via laparotomy, and in 21 a hepaticojejunostomy was performed. Reconstruction of a hepaticojenunostomy was performed in two of these patients. Patients were dismissed from the hospital after a median of 13 days (range 4-156). Four patients presenting with generalized biliary peritonitis required prolonged intensive care. One or more episodes of cholangitis were seen in five patients during follow-up examinations. CONCLUSIONS: Major iatrogenic bile duct injuries are associated with high morbidity and prolonged hospitalization. Interdisciplinary cooperation and early referral to an experienced center is crucial in the management of patients suffering from this affliction. Cholangitis is a marked problem in the follow-up.     

蒿甲醚引起小鼠体内日本血吸虫和曼氏血吸虫皮层变化

蒿甲醚引起小鼠体内日本血吸虫和曼氏血吸虫皮层变化１肖树华，沈炳贵，ＪａｃｋＨＯＲＮＥＲ２，ＢｒｉａｎＡＣＡＴＴＯ３（中国预防医学科学院寄生虫病研究所，世界卫生组织疟疾、血吸虫病和丝虫病合作中心，上海２０００２５，中国；２ＤｅｐａｒｔｍｅｎｔｏｆＣｌｉ...