Chronic endogenous hypercholecystokininemia promotes pancreatic carcinogenesis in the hamster

In order to examine the effect of cholecystokinin on spontaneous and induced pancreatic carcinogenesis in the hamster, two sets of experiments were carried out, one involving long-term hypercholecystokininemia and one involving cancer induction during hypercholecystokininemia. The effect of hypercholecystokininemia, induced by pancreaticobiliary diversion (PBD), was studied for 8 months. Neither PBD animals nor sham-operated controls developed premalignant or malignant pancreatic lesions. However, in the PBD group the mean pancreatic weight, total protein content and DNA content were increased by 30, 29 and 27% respectively. No such increases were found in PBD animals receiving a cholecystokinin-A receptor antagonist during the last 24 days of the experiment. In the cancer induction study, the effect of PBD on N-nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis was studied for 3 months. Putative premalignant pancreatic lesions were diagnosed in all PBD hamsters and in four of 15 sham-operated controls. Pancreatic ductular carcinoma in situ was only found in PBD animals. The [3H]thymidine labeling index of the pancreatic lesions was significantly higher in the PBD group than in the controls. No such increase was observed in PBD animals receiving a cholecystokinin-A receptor antagonist during the last 5 days of the experiment. It is concluded that chronic endogenous hypercholecystokininemia promotes early phase pancreatic carcinogenesis, but does not per se cause development of premalignant or malignant pancreatic lesions in the hamster.      

Trends in the health burden due to urinary tract infection in children in Australia

Objective: To estimate the health burden of urinary tract infection in children less than 15 years of age in Australia and to ascertain whether any significant change has occurred during the past decade. Methodology: The number of children less than 15 years of age who were admitted in New South Wales for urinary tract infection between 1981 and 1994 was ascertained from the Department of Health, and age and sex specific incidence rates were calculated using Australian Bureau of Statistics population data. Costs for inpatient care were calculated using the cost weights from Australia National Disease Related Groups Version 3 for urinary tract infection (DRG 577). The frequency of the four most commonly requested renal tract imaging procedures in children following urinary tract infection and which qualified for Medicare reimbursement were obtained from the Health Insurance Commission for 1984–1994: micturating cystourethrography, intravenous urography, renal ultrasonography, and nuclear medicine renal studies. Results: There were 1203 children who were admitted with urinary tract infection in New South Wales in 1994, at an estimated cost of $A1.6 million. Since 1981, the age standardized annual incidence of urinary tract infection requiring hospitalization has increased from 0.5 to 0.9 per 1000 children, largely because of an increase in the number of young children admitted (from 0.6 to 2.0 per 1000 children less than 5 years of age). In 1994, 46 230 non-inpatient renal imaging procedures were undertaken in children under 15 years of age at a cost of $A5.3 million. Conclusions: Urinary tract infection is an important and increasing health problem for Australian children, particularly for preschool children. Whether this represents a true increase in the incidence of urinary tract infection or improved diagnosis and more intensive management is not possible to establish with this study design. Prospective population based studies are required to assess more completely the frequency with which urinary tract infection occurs in children and any changes that may be occurring.     

Health outcomes in offspring of mothers with breast implants

OBJECTIVE: To examine the occurrence of esophageal disorders, connective tissue diseases, and congenital malformations in children of mothers with breast implants. METHODS: Nationwide register-based follow-up study of all offspring born during 1977 to 1992 to a cohort of 1135 women with breast implants for cosmetic reasons and to a comparison cohort of 7071 women who underwent breast reduction surgery. Cause-specific hospi-talization rates among offspring, relative to those of the general population, were calculated from the Danish National Registry of Patients. RESULTS: Among the 939 children of mothers with breast implants, higher rates of esophageal disorders were observed, but the excess was similar for those born before versus after the implant surgery. Higher than expected hospitalization rates for these conditions were also observed among 3906 children of women who underwent breast reduction surgery. No significant increases in connective tissue diseases or congenital malformations were observed in either the breast implant or breast reduction cohorts. CONCLUSIONS: This first epidemiologic cohort study provides no evidence that silicone breast implants affect risks of esophageal or other disorders in children of the implantees. Rather, the observed risk pattern suggests that a lower threshold exists among both groups of women who have undergone cosmetic breast surgery in seeking professional medical care for problems normally solved outside the hospital.     

Focus-forming ability and surface markers of hamster-human malignant lymphoma hybrids

We have examined the properties of hybrid cells formed by polyethylene glycol-mediated fusion of the GRC+L-73 line of Chinese hamster ovary (CHO) cells with peripheral blood cells from patients with chronic lymphocytic leukemia (CLL) or with bone marrow cells from patients with malignant lymphoma. The results indicate that hybrid cells can be detected by their ability to form "foci" of characteristic morphology in the presence of a monolayer of parental CHO cells and that clones isolated from such foci express aspects of the differentiation status, as detected by immunologic markers, of the human parental cells.     

Hemin does not cause commitment of murine erythroleukemia (MEL) cells to terminal differentiation

The effect of hemin on the differentiation program of murine erythroleukemia (MEL) cells has been investigated. While hemin treatment does induce increased levels of globin mRNA and hemoglobin, it fails to lead to other biochemical changes associated with MEL cell differentiation induced by DMSO and thioguanine. These include increased levels of the nuclear protein IP25 and of the enzyme cytidine deaminase. Clonal analysis of hemin-treated cells revealed that unlike other inducers, hemin does not cause a reprogramming of MEL cells to a specific limitation of proliferative capacity. These observations suggest that hemin differs from DMSO and thioguanine in that it exerts specific effects on globin expression in MEL cells without triggering commitment to the terminal differentiation program.     

兔体内普鲁卡因胺对致颤阈影响的药动学和药效学模型

本文以电刺激兔心室致颤阈作为效应指标,观察了iv PA后药效变化的时间过程,并用药动学、药效学结合模型分析了代谢物形成过程中PA和NAPA的动力学性质,从原药PA和代谢物NAPA不同转运性质角度阐明了两者的效应贡献;它们的效应室内药量与药效符合线性相加模型。     

麻黄中麻黄生物碱的气相色谱测定法

本文应用毛细管气相色谱法,配备氮磷检测器对麻黄中六种生物碱:麻黄碱、伪麻黄碱、去甲麻黄碱、去甲伪麻黄碱、甲基麻黄碱和甲基伪麻黄碱进行分离、测定。对生药样品预处理方法作了较大改进,采用直接碱化醚提法。简化操作步骤。用内标法,线性方程定最测定了国产十二种麻黄,结果与高效液相色谱法基本一致。     

小檗碱对局灶性脑缺血大鼠血小板聚集及血浆TXB2和6－keto－PGF1a水平的影响

以大鼠可逆性大脑中动脉梗塞（ＭＣＡＯ）致局灶性脑缺血为模型，观察小檗碱对大鼠ＭＣＡＯ２４ｈ后血小板粘附、聚集、血栓形成及血浆ＴＸＢ２和ＰＧＩ２生成的影响。结果表明，小檗碱２０ｍｇ·ｋｇ－１·ｄ－１ｉｐｌ，３或５ｄ，明显降低ＭＣＡｏ２４ｈ后血小板粘附性及ＡＤＰ、胶原和花生四烯酸诱导的血小板聚集率，抑制血浆ＴＸＢ２水平。同剂量ｉｐ３或５ｄ，则抑制血栓形成。提示小檗碱可能通过其抗血小板粘附和聚集及影响花生四烯酸代谢而发挥抗脑缺血作用。     

Factors influencing 20-hour increments after platelet transfusion

The 20-hour posttransfusion platelet count determines transfusion policy for patients requiring platelet support, and yet factors influencing the 20-hour count have been poorly defined. The clinical factors influencing both the 1- and 20-hour corrected count increment (CCI), were studied in 623 human leukocyte antigen (HLA)-unmatched platelet transfusions in 108 patients. The 1- and 20-hour CCIs were highly correlated (r = 0.67, p less than 0.001). On average, the 20-hour CCI was 64 percent of the 1-hour CCI. Multiple linear regression analyses identified splenectomy, bone marrow transplantation, disseminated intravascular coagulation, administration of amphotericin B, palpable spleen, and HLA antibody grade as the major factors influencing the 20-hour posttransfusion CCI. Platelet-specific antibodies, number of concurrent antibiotics, clinical bleeding, and temperature did not significantly influence the 20-hour posttransfusion CCI. The 1-hour CCI was the only significant factor influencing the 20-hour CCI in a regression model containing the 1-hour CCI and the above factors. Thus, the same clinical factors exert a major influence on the CCI at both 1 and 20 hours after platelet transfusion, with no evidence that any factor has more influence at 20 hours after transfusion than at 1 hour.