二阶导数分光光度法和紫外分光光度法测定炔诺孕酮炔雌醚片中炔雌醚和炔诺孕酮的含量

采用二阶导数分光光度法对炔诺孕酮炔雌醚片中炔雌醚的含量进行了测定；采用紫外分光光度法测定炔诺孕酮的含量。该方法不需预先分离，简单、快速，其精密度及准确度均较好。同时，采用一般分光光度计进行手动式二阶导数分光光度法对比实验，也获得了满意的结果。     

Clinical and biochemical screening for Smith–Lemli–Opitz syndrome

Smith-Lemli-Opitz syndrome (SLOS) is a multiple congenital anomalies/mental retardation disorder possibly due to a defect of Δ7-sterol reductase, leading to low plasma cholesterol levels and to the accumulation of 7-dehydrocholesterol (7-DHC) and other cholesterol precursors. This study aimed to identify clinical features that could potentially be specific indicators for the clinical diagnosis of SLOS, and to test the reliability of ultraviolet spectrophotometry (UVS) as a biochemical screening procedure for the syndrome. Twenty patients with clinical suspicion of SLOS, referred to 11 Italian paediatricand clinical genetic centres, were collected during 1994. In 10 patients the diagnosis was confirmed biochemically by gas chromatography/mass spectrometry (GC/MS) analysis of serum sterols, whereas in the other 10 patients the serum sterol profiles were normal. A comparison between confirmed SLOS patients and biochemically negative subjects did not show clinical signs specific for the syndrome. UVS measurement of 7-DHC correlated well with GC/MS profiles, showing 100% sensitivity and specificity. Four out of five patients had serum bile acid concentrations below the normal range of controls.     

Distribution of uncrossed axons along the course of the optic nerve and chiasm of rodents

The distribution of the ipsilaterally projecting population of retinofugal axons has been analyzed following injections of horseradish peroxidase (HRP) into the optic tract of adult hamsters and rats to determine whether the topographical segregation of the cells of origin seen in the retina is maintained by their axons throughout the course of the optic nerve and chiasm. Axons are limited to a roughly appropriate topographic location within the intraorbital course of the nerve but this organization changes at levels progressively closer to the optic chiasm. Immediately rostral to the chiasm labelled profiles are found dispersed across most of the cross-sectional area of the nerve. This dispersal is maintained within the region of the optic chiasm where a complex rearrangement of ipsilaterally projecting axons takes place. The results show that axons are not retinotopically organized along the entire length of the optic nerve. The order of axons changes along the course of the nerve and in the optic chiasm. The change seen within the intracranial course may indicate a chronotopic re-sorting of axons prior to the optic tract where the organization of axons has previously been interpreted as a map of time of axon arrival.     

差示分光光度法测定牛黄类中成药中胆红素的含量

本文利用胆红素溶液在光照下易氧化变色及其吸收光谱发生显著变化的性质,在波长453 nm处,测其光照前后的吸收度差值(△A),△A与胆红素溶液浓度呈线性关系,对含牛黄的中成药(六应丸,六神丸和牛黄消炎丸)中胆红素进行了定量,并对其它组分进行了光照试验,排除了光照对其它组分的影响,从而确定了此法的可行性。     

Photofrin II localization in rat cecum

Laser excitation of photodynamic agents localizing in colonic tumors may allow the early diagnosis and treatment of colon cancer. The efficacy of these agents requires a high ratio of tumor to background photosensitizer accumulation and fluorescence. To assess normal colonic background fluorescence and hematoporphyrin accumulation 31 rats were studied after an intravenous injection of Photofrin II (PF-II) at a dose of 5 mg/kg. An increase in mucosal fluorescence and porphyrin content was noted in the cecum 24 hours after injection. Cecal accumulation of PF-II may affect its efficacy in the localization and treatment of cecal tumors. Further investigation into the mechanism and clinical significance of this finding is needed.     

A retrospective study of the relationship between birth history and handedness at six years

Bakan's hypothesis that sinistrality is caused by perinatal insult was investigated by attempting to relate the handedness of 1094 six-year-old children to many aspects of their birth history ascertained from hospital records. Handedness of the children and their families was obtained by questionnaire. A secular increase in the frequency of sinistrality was noted, from 6.2% among grandparents to 17.5% among the children. More boys were left-handed than girls. Only two aspects of birth history predisposed to sinistrality: boys born by breech delivery and children born to primiparous mothers over 38 years old were more likely to be left-handed.     

In vivo modulation of norepinephrine-induced cerebral oxygenation states by hypoxia and hyperoxia

The effect of intravenous norepinephrine (NE) administration on three O2-dependent parameters of cerebral oxygenation was studied in the parietal cortex of skull intact anesthetized rats. Reflectance spectrophotometry was used to measure in vivo changes in cortical hemoglobin saturation (Hb/HbO2), blood volume (BV), and cytochrome c oxidase (cyt. a,a3) oxidation-reduction state. The influence of arterial pressure of oxygen (paO2) on norepinephrine-induced changes in cortical microcirculatory O2 delivery and cyt. a,a3 redox state was tested under conditions of normoxia, hypoxia, and hyperoxia. Norepinephrine produced cyt. a,a3 redox changes which were independent of compensatory alterations in cortical blood volume and changes in systemic blood pressure at the tested physiological extremes. During normoxia, NE caused dose-dependent systemic pressure-related increases in the oxidation level of cyt. a,a3. Conversely, in hypoxia NE caused a reduction. Microcirculatory and cyt. a,a3 redox responses to low doses of NE during hyperoxia were similar to those obtained at high doses during normoxia. The kinetic pattern of changes in hemoglobin saturation, cyt. a,a3 redox state, and cortical blood volume during normoxia and hypoxia was consistent with direct alteration in oxygen delivery to the respiratory chain and possible modification of cerebral oxidative metabolism. Blood-brain barrier alterations and vascular smooth muscle resistance changes to NE under tested conditions of oxygenation are postulated to be responsible for the observed results.     

阿糖腺苷脂质体含量及包封率测定

利用紫外分光光度法和高效液相色谱法测定阿糖腺苷(Ara-A)脂质体的含量及包封率(EN%)。结果表明:紫外分光光度法简便、快速,其含量测定回收率为100.64±0.39%;而 HPLC 法可以在有水解产物腺嘌呤存在的条件下进行分离检测,最低检出量为0.6ng,该法灵敏度高,准确性佳。     

紫外分光光度法测定呱西替柳胶囊中呱西替柳的含量

采用紫外分光光度法测定呱西替柳胶囊中呱西替柳的含量。当呱西替柳的甲醇溶液在浓度为１５～５０μｇ／ｍｌ时，与吸收度呈很好的线性关系（ｒ＝０．９９９８），平均回收率为１０１．０％，ＲＳＤ为０．８８％（ｎ＝６）。该方法简单、快速，结果满意。     

Birth order and multiple sclerosis

No significant difference in birth order and risk of multiple sclerosis (MS) was found in a large-scale investigation employing 2 different study methods: case-control and comparison of birth order with expected distribution. This finding is at variance with conflicting results of 2 recently published investigations. Our findings suggest that birth order cannot be used as a surrogate for age-of-infection, but must be measured directly in further studying the role of delayed childhood infection in the pathopoiesis of MS.