In vitro studies of intragastric digestion

Following consumption of a meal, 99% of the large food particles are emptied only after intragastric fragmentation has reduced their diameter to less than 2 mm. Anin vitro model was constructed to evaluate some of the factors which may play a role in the process of intragastric digestion. Gastric mixing of food was simulated in a silicone rubber tube (ID 19 mm) placed in a peristaltic pump. Peristaltic waves progressed upwards along the tube at a frequency of 0, 1, or 3/min, reducing the internal diameter of the tube to 5 mm. Cooked chicken liver particles (2–2.8 mm in diameter) were placed in the tube with one of the following: (1) 150 mM NaCl, (2) 150 mM HCl with or without pepsin, or (3) phosphate buffer at pH 7, 5.4, or 2.6 + pepsin. After 30 min, the extent of particle reduction and of solubilization of proteins were determined and expressed as percent of the initial liver weight. The diameter of liver particles was reduced to a greater extent in NaCl than in pH 7 buffer or acid solutions with or without pepsin. In contrast, the amount of proteins solubilized was enhanced two- to threefold by acid pepsin solutions compared to NaCl or pH 7 phosphate. The presentin vitro studies suggest that changes in motor and/or secretory activity of the stomach significantly modify intragastric digestion.     

Characterization of rat hyperplastic bile ductular epithelial cells in culture andin vivo

A novel intrahepatic biliary cell culture/in vivo transplantation system has been developed with an essentially pure population of bile ductular epithelial cells isolated from rat liver 6–12 weeks after bile duct ligation. In primary culture, these cells retain staining strongly for -glutamyltranspeptidase and glutathione S-transferase P. The cytoplasm of cultured bile ductular cells reacts with an anti-laminin antibody, but loses immunoreactivity with a monoclonal anti-cytokeratin 19 antibody. Semiconservative DNA synthesis in the cultured cells was dependent upon the continued presence of 10% fetal calf serum in the medium. Replicating bile ductular cells could be subcultured for a finite number of passages. In addition, freshly isolated bile ductular epithelial cells gave rise to well differentiated bile ductular structures when transplanted into the interscapular fat pads of syngeneic recipient rats.Presented at the Proceedings of the International Meeting on Normal and Neoplastic Growth in Hepatology, Bari, Italy, June 1989.This work was supported by USPHS Grant RO1 CA39225 to Dr. Sirica by the National Cancer Institute, Department of Health and Human Services.     

Phenotypic diversity in siblings with partial androgen insensitivity syndrome

The androgen insensitivity syndrome is a heterogeneous disorder with a wide spectrum of phenotypic abnormalities, ranging from complete female to ambiguous forms that more closely resemble males. The primary abnormality is a defective androgen receptor protein due to a mutation of the androgen receptor gene. This prevents normal androgen action and thus leads to impaired virilisation. A point mutation of the androgen receptor gene affecting two siblings with partial androgen insensitivity syndrome is described. One had cliteromegaly and labial fusion and was raised as a girl, whereas the other sibling had micropenis and penoscrotal hypospadias and was raised as a boy. Both were shown to have the arginine 840 to cysteine mutation. The phenotypic variation in this family is thus dependent on factors other than abnormalities of the androgen receptor gene alone.     

The procoagulant activity of red blood cells from patients with severe preeclampsia

OBJECTIVE: Our purpose was to determine whether red blood cells from patients with severe preeclampsia may exhibit increased membrane exposure of procoagulant phospholipids (i.e., phosphatidylserine), which may initiate intravascular clotting and platelet activation. STUDY DESIGN: The study group comprised 28 women: 9 with severe preeclampsia in the third trimester of pregnancy, 10 normotensive with uncomplicated pregnancies, and 9 age-matched, nonpregnant, healthy women. The exposure of phosphatidylserine on the outer membrane phospholipid layer was analyzed with use of isolated, washed red blood cells that were added as a source of phospholipids to a “prothrombinase” coagulation complex. RESULTS: The resultant thrombin formed was measured by an amidolytic assay. Thrombin generation significantly increased on the addition of red blood cells from women with preeclampsia (741 ± 132 mU/ml/min) compared with red blood cells from normotensive pregnant (422 ± 228 mU/ml/min) and nonpregnant women (316 ± 268 mU/ml/min, p = 0.0008). CONCLUSION: This study indicates that in patients with preeclampsia the red blood cells exhibit a significant procoagulant surface that may trigger thrombin formation, thereby playing a role in the hypercoagulable state.(Am J Obstet Gynecol 1997;177:6)     

Proliferative lesions of oviduct and uterus in CD-1 mice exposed prenatally to tamoxifen

Tamoxifen (TAM) is widely used as adjuvant breast cancer therapy after surgery and as a chemopreventive agent in women of child-bearing age. However, TAM therapy has been shown to result in an increased incidence of endometrial carcinoma in women. The present study was designed to investigate the effects of TAM (5 mg/kg and 7.5 mg/kg body wt) given i.g. to pregnant CD-1 mice (1x/day, days 12 through 18 of gestation) on their female offspring. Progressive proliferative hyperplasia of the oviduct was frequently seen in TAM-exposed offspring, reaching 100% incidence by 52 weeks in both treatment groups. These females also developed progressive proliferative uterine lesions, including moderate/severe cystic endometrial hyperplasia (34-50%) and polypoid adenomas (27-30%) between 53 and 78 weeks. Deciduomas (15%) occurred at young ages (12 and 24 weeks) while leiomyomas (14%), a malignant leiomyosarcoma, and ovarian granulosa cell tumors (14%), were found between 72 and 78 weeks. Our findings thus suggest a strong association between transplacental TAM and reproductive tract abnormalities in female CD-1 mice.      

Multigenic control of skin tumor susceptibility in SENCARA/Pt mice

Skin tumors induced in mice by initiation-promotion (2 microg DMBA-2 microg TPA) protocols were found to be under multigenic control. Eighty- one N2 mice from the cross (BALB/cAnPt x SENCARA/Pt)F1 x SENCARA/Pt that were either solidly resistant (no papillomas) or highly susceptible (> or = 7 papillomas/mouse) were subjected to a 'genome scan' using 89 microsatellite markers to check for associations with susceptible and resistant phenotypes. A locus on Chr 5 (Skts4) was found to control the susceptibility of SENCARA/Pt mice and the resistance of BALB/cAnPt mice to papilloma formation. In addition, higher than expected linkage scores were seen for the markers D9Mit271, D11Mit268 and D12Mit56. Further work is required to establish whether genes determining papilloma formation are located in these regions of the genome. In general, no evidence was seen for loss of heterozygosity in microsatellite markers on Chrs 5, 9 and 11 in 17 microdissected papillomas from (BALB/c x SENCARA)F1 hybrid mice.      

Mortality: What Are the Roles of Risk Factor Prevalence,Screening, and Use of Recommended Treatment?

CONTEXT: Despite advances in early detection and prevention of cervical cancer, women living in rural areas, and particularly in Appalachia, the rural South, the Texas/Mexico border, and the central valley of California, have had consistently higher rates of cervical cancer mortality than their counterparts in other areas during the past several decades. METHODS: This paper reviews the published literature from 1966 to July 2002 to assess three potential pathways underlying this excess mortality--high human papilloma virus (HPV) prevalence, lack of or infrequent screening and advanced disease at diagnosis, and under-use of recommended treatment and shorter survival. FINDINGS: Living in rural areas may impose barriers to cervical cancer control, including lack of transportation and medical care infrastructures. Population characteristics that place women at greater risk for developing and dying from cervical cancer, such as low income, lack of health insurance, and physician availability, are concentrated in rural areas. Published data, however, are insufficient to identify the key reasons for the observed mortality patterns. CONCLUSIONS: At this time, given the lack of definitive evidence in the published literature, decisions about priorities in areas with high rates of cervical cancer mortality will depend on knowledge of current levels of screening, incidence, and stage distribution; and service delivery infrastructures, resources, and acceptability of interventions to the target population.     

角膜塑型术矫正近视二年后的临床观察

目的 :探讨角膜塑型术 (Orthokeratology ,简称Or tho K镜 )矫正近视的远期疗效 ,了解其对近视的矫正及控制近视进展的效果。并观察其安全程度。方法 :配戴Ortho K镜二年以上的青少年近视眼患者 ,共 86例 16 6眼 ,平均年龄(15 .5± 2 .6 )岁 ( 10～ 2 5岁 ) ,平均屈光度 ( - 4 .0 2± 1.78)D( -1.5～ - 7.0D)。对配戴前、后的角膜曲率、角膜地形图、角膜厚度、眼轴、眼压进行检测 ,平均观察期为 ( 2 8.2 5± 3.74 )个月。结果 :配戴前后平均裸眼视力分别为 0 .2 1± 0 .10和0 .99± 0 .2 3,差异有非常显著性 (P <0 .0 1) ;配戴前后角膜水平曲率均值分别为 ( 4 3.0 5± 1.10 )D和 ( 4 0 .84± 1.38)D ;配戴前后眼轴 (眼球前后径 )均值分别为 ( 2 4 .93± 0 .82 )mm和( 2 5 .16± 0 .82 )mm ,每年眼轴增长均值为 ( 0 .12± 0 .4 1)mm ;配戴前后角膜厚度均值分别为 ( 0 .5 6 5± 0 .0 30 )mm和 ( 0 .5 5 7±0 .0 34)mm ,配戴后角膜厚度平均变薄 0 .0 0 9mm ,差异有显著性 (P <0 .0 1) ;配戴前后眼压均值分别为 ( 15 .95± 2 .92 )mmHg和 ( 15 .35± 2 .6 0 )mmHg ,配戴后眼压平均下降 0 .6 0mmHg,差异有显著性 (P <0 .0 1)。配戴Ortho K镜期间有 79眼发生过角膜点状浸润 ,占配戴眼数的 4 7.31%。结论 :Or t     

62例咽旁间隙肿瘤临床分析

目的：探讨咽旁间隙肿瘤的诊断和治疗方法及熟悉咽旁间隙解剖与肿瘤关系。方法：回顾性分析62例咽旁间隙肿瘤的临床资料。结果：咽旁间隙肿瘤中病理类型较多,但以神经鞘膜肿瘤比例较大,占41.9%,混合瘤22.6%,畸胎瘤、错构瘤、脊索瘤、恶性淋巴瘤及脑膜瘤等共占35.5%。进行以颈侧入路为主的4种手术入路,2例肿瘤复发（1例神经鞘膜瘤,1例转移癌）,再次手术治愈,其余均一次性手术治愈。结论：咽旁间隙肿瘤临床表现复杂,病理类型多样,肿瘤预后较好。其诊断较难,除症状体征外,CT、MRI及B超对咽旁间隙肿瘤的诊断有重要价值。手术径路是根据患者体征、影像学特征结合肿瘤位置、大小及性质而最终确定。颈侧入路为主要手术途径,气管切开为预防窒息措施。