Relationship of clomiphene dose and patient weight to successful treatment

Our objective was to examine the relationship between patient weight and the dose of clomiphene required for pregnancy so as to assess the validity of recommendations that the dose of clomiphene be limited to 100 mg. We retrospectively analysed the weight-dose relationship in 1681 clomiphene pregnancies and the relationship between dose and pregnancy, births, multiple births, number of pre-ovulatory follicles and endometrial thickness in 2841 cycles of clomiphene treatment, 25- 250 mg, for 5 days before intrauterine insemination (IUI). Doses of clomiphene >100 mg/day were used before pregnancies in 27.4% of patients who weighed >90 kg and in 14.7% of all pregnancies. In IUI cycles, pregnancies and births, but not multiple births or abortions, were related to dose. An increase in dose from 25 to 100 mg resulted in higher pregnancy and birth rates, and in an increase in the average number of pre-ovulatory follicles > or =12 mm in diameter, from 2.0 to 2.8, with no additional increase at higher doses. Endometrial thickness and cycle day of insemination were not related to dose. We conclude that doses of clomiphene may safely be increased beyond 100 mg, and that doses > or =100 mg are required in significant numbers of patients.      

Allorecognition by murine natural killer cells: lysis of T-lymphoblasts and rejection of bone-marrow grafts

Summary: Natural killer (NK) cells of inbred mice reject allogeneic bone-marrow cells, and NK cells of F1 hybrid mice can reject parental bone-marrow cells (hybrid resistance). In some cases these patterns of rejection can be mimicked in vitro by utilizing IL-2 cultured NK effector cells and allogeneic or parental T-lymphoblasts as target cells. Lysis of allogeneic parental targets in vitro can be explained on the basis of the missing self hypothesis. Subsets of NK cells that bear non-overlapping MHC class I inhibitory receptors belonging to the Ly49 family lyse allogeneic targets because they do not express self class I molectiles of the NK cell donor. Parental strain targets are lysed because they do not express all of the self class I antigens of the Fl hybrid, and hence fail to deliver inhibitory signals to all subsets of Fl NK cells. The expression of Ly49 receptors on NK cells is regulated by liost MHC to ensure maximal sensitivity to alterations in self class I molecules and to prevent autoreactivity. In many instances, however, the rejection of allogeneic bone marrow cells in vivo cannot be readily explained by the missing self hypothesis. In these instances, it appears that rejection is initiated by class 1 MHC receptors on NK ceils Out recognize allogeneic class I molecules as non-self, and activate rather than inhibit NK cell function.     

Occupational exposure to mixtures of organic solvents increases the risk of neurological symptoms among printing workers in Hong Kong

LEARNING OBJECTIVES: Summarize the nature and extent of exposure to organic solvents to which printing workers in this study were subjected. Compare the numbers of neurological symptoms in exposed and non-exposed workers and how they related to level of exposure, as defined by specific job title or by air sampling. Clarify the relationship between exposure to organic solvents and individual psychoneurological and other symptoms. ABSTRACT: The health effects of low-dose occupational exposure to organic solvents remains unclear. A cross-sectional survey was conducted among 762 male printing workers to assess the impacts of exposure to mixtures of n-hexane, toluene, isopropyl alcohol, and benzene on neurological and other symptoms. After controlling for age, smoking, alcohol drinking, past exposure history, working hours and shift work, current exposure to solvent mixtures was significantly associated with the total number of neurological symptoms and with the prevalence of specific symptoms of the nervous system and mucous membrane irritation. The adjusted odds ratio of neurovegetative lability (1.7-5.9), abnormal or reduced smell (1.6-4.1), memory loss (1.8), and mucous membrane irritation symptoms (1.5-4.6) significantly increased in the exposed group, especially when the summation index of exposure exceeded one.     

Symptomatic venous thromboembolism in Chinese patients after gynecologic surgery: incidence and disease pattern

BACKGROUND: Venous thromboembolism is a common cause of postoperative morbidity and mortality in Caucasian populations, but it is widely believed that this complication is rare in Chinese. METHODS: We conducted a retrospective study from January 1998 to December 2000. Women with thromboembolic diseases after gynecologic surgery were identified and their medical records were reviewed. RESULTS: During the study period, thirty-one women were diagnosed as having thromboembolic disease after gynecologic surgery. Over the study period, the total number of operations was 6077, giving an incidence of 5.10/1000 operations. There were two cases of pulmonary embolism and the others had deep vein thrombosis of which 90% were limited to calf veins only. The incidences were significantly higher in 1999 and 2000 (7.59 and 6.85/1000 operations, respectively) than that in 1998 (1.7/1000 operations) (P = 0.015), after a case of maternal death due to pulmonary embolism in early 1999. Most cases of thromboembolism were diagnosed after major surgery for malignancy (n = 14) or benign conditions (n = 12). In the remaining cases, three had evacuation of the uterus for retained products of conception and two had laparoscopy for suspected ectopic pregnancies. CONCLUSIONS: Thromboembolic disease is not uncommon among Chinese women after gynecologic surgery. The incidence is similar to that of the Caucasian population, although the sites of vascular occlusion were different. The long belief that thromboembolism is rare among Chinese is at least partly due to under-diagnosis.     

Optimal pulse sequence for imaging hepatic metastases

For magnetic resonance (MR) imaging studies in which the diagnosis is dependent on image contrast, it is essential that an optimized imaging technique be used. Using detection of hepatic metastases as an example, the authors describe a rational strategy for optimizing MR imaging technique. First, for a single patient with proved hepatic metastases, a variety of imaging sequences is discussed and evaluated, leading to characterization of the patient's hepatic tissues. Then the characteristics of the tissues of a representative patient population are presented. These are used to determine two optimal pulse sequences that maximize the achievable signal difference-to-noise ratio achievable in a fixed imaging time. The recommended imaging sequence for detection of hepatic metastases at 0.15 T is either a three-dimensional volume spin-echo (SE) sequence with echo time (TE) = 12 msec and repetition time (TR) = 184 msec or a multisection inversion recovery sequence with TE = 22 msec, inversion time = 250 msec, and TR = 1,375 msec. The variation of this optimum pulse sequence with field strength is also presented.     

女儿茶多糖NLC-A的分离纯化及化学结构

女儿茶为民间常用中草药。经水提取,去蛋白及小分子杂质得到女儿茶多糖(NLC-A)粗制品。再经Cellex D,Sepharose 6B和Sephadex G-100相继柱层析,得到均一组分NLC-A,分子量为1.2×10⁴,NLC-A经全水解,甲基化反应,过碘酸盐氧化,Smith降解,KI-I₂反应和IR证明其结构为以α(1→4)-D-葡萄糖为主链,并在o-6位有分枝的葡聚糖。