The angiogenic switch in hamster buccal pouch keratinocytes is dependent on TGFbeta-1 and is unaffected by ras activation

This study was undertaken to investigate the mechanisms by which Syrian hamster buccal pouch keratinocytes treated in vivo with 7,12- dimethylbenz[a]anthracene (DMBA), switch from an angio-inhibitory to an angiogenic phenotype. Cells were cultured from pouches at various times after exposure to carcinogen and their angiogenic activity assessed. The angio-inhibitory activity present in conditioned media from normal cells was lost as early as 3 weeks after carcinogen treatment, resulting in weak expression of angiogenic activity. By 5 weeks, cells had become strongly angiogenic due to the secretion of high levels of TGFbeta-1, a potent angiogenic factor. Because the switch to high levels of secreted TGFbeta-1 occurred at the same time as the activation of the H-ras oncogene, non-angiogenic cell lines lacking an activated H-ras oncogene were stably transfected with mutant H-ras and their transformed and angiogenic phenotypes were evaluated. Although ras transfection drove two of the three cultured cell lines to anchorage independence and modestly increased their ability to clone in low serum, it had no effect on the angiogenic phenotype or on the level of secreted active TGFbeta-1. These results demonstrate that the angiogenic phenotype in the hamster buccal pouch model of oral carcinogenesis develops in a step-wise fashion with an early decrease in the production of an inhibitor of angiogenesis and a subsequent marked increase in the secretion of the inducer TGFbeta-1. Although the activation of the H-ras oncogene contributed to anchorage independence, it did not affect the expression of the angiogenic phenotype in this model system.      

Automatic implantable cardioverter-defibrillator: radiographic appearance

The automatic implantable cardioverter-defibrillator is used in patients with ventricular tachyarrhythmias resistant to medical or surgical therapy. The device, which has a unique radiographic appearance, senses ventricular tachycardia or fibrillation and automatically delivers a cardioverting or/defibrillating electric shock.     

Cerebral astrocytomas: histopathologic correlation of MR and CT contrast enhancement with stereotactic biopsy

Gadolinium-labeled diethylenetriaminepentaacetic acid was used as a contrast agent for stereotactic magnetic resonance (MR) imaging in six selected patients with brain tumors who underwent stereotactic biopsy. Regions of contrast enhancement demonstrated by computed tomography (CT) and MR imaging in four of the six patients correlated with areas of malignant neovascularity and endothelial proliferation within solid tumor. Radiation necrosis produced contrast enhancement indistinguishable from that of recurrent neoplasm. Isolated tumor cells within intact white matter were identified in biopsy specimens obtained outside of regions that were depicted as abnormal by contrast material-enhanced CT, as well as by precontrast and postcontrast T1- and T2-weighted MR images.     

输卵管妊娠的干预

由丁敏感的妊娠试验（尿液和血清中）及高分辨阴道超声检查都被综合在诊断法则中（Romero 1985，Cacciatore 1990，Ankum 1993a，Ankum 1993b），异位妊娠的诊断现在常可通过非侵入性的方法作山。这些法则，连同临床医生及患者对危险因素所共同增加的意识利知识，使异位妊娠的早期和准确诊断成为可能。结局，异何妊娠的临床表现从一个威胁生命的疾病转变为一个更为良性的状况，进而导致了现有治疗方法选择的较人改变。由于治疗干预常常可能在患者情况恶化及输卵管完整性丧失前进行，从而改善临床结局，降低急症手术有关费用。而对将来需要生育者，保守性手术已成为一种选择（Stromme 1962，DeCherney 1979，Bukovsky 1979）。     

Advanced glycation end products, their receptors and diabetic angiopathy

Hereditary Neuralgic Amyotrophy (HNA) is an autosomal dominantly inherited recurrent focal neuropathy affecting mainly the brachial plexus. Linkage to markers on chromosome 17q25 was found in 1996 and subsequent reports confirmed linkage of HNA to this locus. Recently a family with a chronic undulating rather than remitting-relapsing clinical course of HNA was described by a Dutch group. This family did not have linkage to the 17q25 locus. Here we describe for the first time clinically and genetically two families with classic remitting-relapsing HNA that are not linked to the previously described HNA locus on chromosome 17q25. These results demonstrate that clinically homogeneous classical HNA is genetically heterogeneous.     

The presurgical management with erythrocytapheresis of a patient with a high-oxygen-affinity, unstable Hb variant (Hb Bryn Mawr)

BACKGROUND: Hemoglobin (Hb) Bryn Mawr is an unstable Hb variant resulting in congenital hemolytic anemia. This variant Hb also has an increased affinity for oxygen. The perioperative transfusion management of this disorder is described, and the first genomic analysis of this Hb variant is given. CASE REPORT: An 11-year-old boy, heterozygous for Hb Bryn Mawr, was referred for cholecystectomy. Sequence analysis of genomic DNA confirmed that the patients was heterozygous for a T–>C transition in the codon for amino acid 85, causing a substitution of serine for phenylalanine in the beta-globin chain. On the basis of whole-blood O2 dissociation studies, projected tissue O2 delivery would have been suboptimal during general anesthesia; therefore, a partial red cell exchange transfusion was performed to lower variant Hb and prevent tissue hypoxia during surgery. The red cell mass to be exchanged (50%) was determined from the calculated increase in O2 delivery capacity required to maintain an O2 extraction of 4 to 5 mL of O2 per dL of whole blood. The p50 of whole blood from the patients immediately after the exchange transfusion was 16.0 torr. At the time of surgery, the p50 was normal (25.9 torr). The patient's whole blood 2,3 DPG levels were 4.70 mmol per mL of red cells (before transfusion) (normal range=4.8 +/? 0.3 mmol/mL red cells), 4.07 mmol per mL of red cells (immediately after transfusion), and 4.55 mmol per mL of red cells (48 hours after transfusion). CONCLUSION: This patient with Hb Bryn Mawr was prepared for surgery with a partial exchange transfusion to prevent tissue hypoxia during anesthesia. Decreased 2,3 DPG levels immediately after transfusion resulted in increased O2 affinity of whole blood; however, 48 hours after exchange transfusion, a normal p50 (due to both removal of variant Hb and regeneration of 2,3, DPG) was observed. Partial exchange transfusion is useful in the preoperative management of patients with Hb variants characterized by increased O2 affinity.     

Early prostate cancer: diagnostic costs of screening transrectal US and digital rectal examination

A screening study with transrectal ultrasound (US) and digital rectal examination to diagnose early prostate cancer was performed to calculate diagnostic costs. The total costs of screening 784 men were $130,400 with transrectal US and $41,080 with digital rectal examination. Per diagnosed cancer, the costs were $6,520 for transrectal US and $4,108 for digital rectal examination, a difference of 37%. The costs per early diagnosed cancer (stage A or B) were $7,671 and $5,869 for transrectal US and digital rectal examination, respectively--a difference of 23%. The costs per early cancer that would have been advanced if diagnosed without screening were $22,177 for transrectal US and $28,528 for digital rectal examination--a difference of 22% in favor of transrectal US. Equations for these relative costs were generated for transrectal US and digital rectal examination. Costs are related to changes in prevalences and to changes in the stages of prostate cancer when diagnosed without screening.