Fourteen-Day Inhalation Study in Rats, Using Aged and Diluted Sidestream Smoke from a Reference Cigarette: II. DNA Adducts and Alveolar Macrophage Cytogenetics

The chemical constituents of cigarette smoke are greatly dilutedin environmental tobacco smoke (ETS). In the typical indoorenvironment where cigarettes are smoked, the mean value of respirablesuspended particles is approximately 0.1 mg/m³. In this study,we used aged and diluted sidestream smoke (ADSS) of 1R4F Universityof Kentucky research cigarettes as a surrogate for ETS and exposedSprague-Dawley rats nose-only to 0, 0.1, 1.0, and 10 mg wettotal particulate matter (WTPM)/m³ for 6 hr per day for 14 consecutivedays. DNA from lung, heart, larynx, and liver was tested foradduct formation after 7 and 14 days of exposure and after 14days of recovery. In addition, alveolar macrophages from animalsexposed for 7 days were examined for chromosomal aberrations.Exposure-related DNA adducts were not observed in any of theanimals at 0.1 or 1.0 mg WTPM/ m³, which represent ambient and10-fold exaggerated ETS concentrations, respectively. Slightdiagonal radioactive zones, characteristic of adducts observedin human smokers and in animals exposed to mainstream smoke,were observed, but only in lung and heart DNA of animals exposedto the highest concentration of ADSS (10 mg WTPM/m³), a 100-foldexaggeration of typical field measurements of ETS. The meanrelative adduct labeling values (±SE) were 8.7 (±0.2)adducts per 10' nucleotides for lung DNA and 5.7 (±0.7)adducts per 10' nucleotides for heart DNA after 14 days of exposure.No elevation in chromosomal aberrations was observed in alveolarmacrophages. These results indicate a no-observed-effect-level(NOEL) of 1.0 mg/m³ for DNA adduct formation in lung and heartand a NOEL of at least 10 mg/m³ for the induction of chromosomeaberrations in alveolar macrophages under the conditions ofthis study.     

THERAPY OF PRIMARY HYPOTHYROIDISM WITH L-TRIIODOTHYRONINE: DISCORDANT CARDIAC AND PITUITARY RESPONSES

Cardiac systolic time intervals were studied in ten patients with primary hypo-thyroidism before and during therapy with increasing doses of oral L-triiodo-thyronine (L-T3). Therapy was increased sequentially from 10, 20, 25 to 50 μg of L-T3 daily on a monthly basis. On L-T3, 20 to 25 μg/day, cardiac systolic time intervals and other peripheral responses to thyroid hormone including serum cholesterol concentration, serum creatine phosphokinase (CPK) activity, and basal metabolic rate had normalized. However, serum thyrotrophin (TSH) levels and peak TSH responses to thyrotrophin-releasing hormone (TRH) remained elevated on these doses of L-T3. As the dose of L-T3 was increased from 20 to 50 μg/day, mean basal serum TSH levels decreased from 55 to 16 μu/ml, and the peak TSH response to TRH decreased from 243 to 58 μu/ml ( P < 0.001) while systolic time intervals did not decrease further. Changing to L-thyroxine (L-T4) therapy at this point resulted in further suppression of TSH secretion, without significantly altering systolic time intervals or the other peripheral responses to thyroid hormone. These data suggest (a) that some biological responses to thyroid hormone were normalized on lower doses of L-T3 than were required to normalize TSH secretion, and (b) that higher doses of L-T3 or substituting L-T4 therapy could suppress TSH secretion further without altering the other peripheral responses to thyroid hormone.     

粉末药材显微鉴定研究Ⅰ.

中药成药制剂——丸散锭丹大多是直接采用各种粉末药材配制而成。一种成药往往包括有数种至数十种粉末药材。利用显微观察是鉴别这类成药制剂最快速准确的科学方法之一。要比较全面地从事成药制剂的鉴定,必须首先研究清楚制做成药的各种原料药材的粉末特征。为此,我们以中国药典一部(1963年版)收载的丸散锭丹的主要原料药材为主,系统地进行粉末特征的研究。本文将分期报导其中的70种,并附有粉末特征图。     

ACUTE NONSPECIFIC CARDITIS WITH ADVANCED HEART BLOCK IN MALAYSIANS

Acute nonspecific carditis with advanced heart block is rare. We observed nine cases with complete heart block and one with Mobitz type II block over an eight and a half year period. Temporary cardiac pacing was instituted in all while permanent pacing was required in six patients. No death was recorded.     

成年犬种植体与非牙龈粘膜组织间龈沟液酶水平和粘膜炎症的关系

目的 探讨在口腔环境下，种植体的软组织界面为非牙龈粘膜时，龈沟液（GCF）的量及其中天冬氨酸转氨酶（AST）和碱性磷酸酶（ALP）含量与种植体周围炎症的关系。方法 选择4只狗，按标准方法在狗的下颌磨牙区相应牙槽骨上以唇舌侧方向穿过牙槽黏膜植入一阶段式钛种植体，形成种植体与牙槽黏膜界面的情况。共植入种植体7枚。分别观察1、2．4、6周。每1～2周收集龈沟液及相应处自然牙龈沟液，定量后用生化分析仪检测其中ASF、ALP含量。结果 实验期间种植体均稳定，种植体周围黏膜组织均有不同程度炎症表现；整个实验期间，自然牙的GCF、ASF、ALP含量分别波动在0．9～1、27～30、1～9u／L之间，这三项指标很低且稳定；而种植体的这三项指标波动范围分别是2～11、50～306、5～55u／L。结论 当口腔内种植体周围软组织为非牙龈粘膜时，其GCF的量及其中ASF、ALP含量变化与软组织炎症程度可能一致。     

Population based standards for pulmonary function in non-smoking adults in Singapore

Abstract Ethnic differences in lung function are well recognized, hence the use of normative data should therefore be based on reference equations that are derived specifically for different ethnic groups. We have collected data ( n =406) for population-based reference values of lung function from randomly selected samples of healthy non-smoking adults of both gender (aged 20–79 years) for each of the three major ethnic groups (Chinese, Malay and Indians) in Singapore. Lung function forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), FEV₁/FVC, diffusion capacity (transfer factor) for carbon monoxide (DLCO), total lung capacity (TLC), residual volume (RV), RV/TLC and functional residual capacity (FRC) was measured using standardization procedures and acceptability criteria recommended by the American Thoracic Society. Lung function values were predicted from age, height, weight, body mass index (BMI) and transformed variables of these anthropometric measures, using multiple regression techniques. Ethnic differences were demonstrated, with Chinese having the largest lung volumes and flow rates, and Indians the smallest. These prediction equations provide improved and additional (TLC, RV, RV/TLC, FRC) population-based reference values for assessment of pulmonary health and disease in Singapore