Chest radiography: a survey of techniques and exposure levels currently used

In diagnostic radiology, the routine measurement of exposure levels for a reference patient is an important part of an effective quality assurance program. In the United States, chest radiography is the most frequent examination and has the lowest exposure level of all radiologic examinations. We estimated the amount of exposure an average patient received from both manual and automatic exposure-controlled radiographic techniques by using a "patient-equivalent" chest phantom during measurements. A densitometric procedure was used to assess processor performance. The mean exposure from 194 chest systems was 20 mR (5.16 X 10(-5) C/kg); the mean film density, 1.38; and the mean processing speed, 108. It is interesting to note that a wide range of radiographic techniques, processing conditions, and screen-film speeds are currently being used. With the information given in our study, investigators can begin to identify the problems that lead to unusual exposure levels and, perhaps, poor image quality.     

保存12周的红细胞

现代液体红细胞保存体系运行良好,使一个国家供应的异体红细胞安全、廉价,并且有效率达到95％。现代红细胞保存系统在临床上用途广泛,如可为自身输血提供血液,可为战场上的手术输送血液,避免献血者接触新生儿,显然如果延长红细胞的保存期将会有更大的益处。然而,由于衰老的红细胞具有使血流不畅,细胞破裂后一些有毒性的脱出物可能使外伤病人的死亡率增加和导致输血相关急性肺损伤(TRALI),进一步研究建立更好的红细胞保存体系仍然很重要。     

Ectopic pregnancy with postcoital contraception – a case report

The incidence of ectopic pregnancies is increasing. Common risk factors are tubal pathology, previous tubal surgery, previous ectopic pregnancy, intrauterine device use and embryo transfer. Levonelle-2^®, a progesterone-only postcoital contraceptive works by a combination of mechanisms including ovulation inhibition, prevention of fertilization, and inhibition of implantation. It is 85% effective and there have been 12 reported cases of ectopic pregnancy in the UK with its use. It is believed that progesterone slows the intratubal migration of the fertilized ovum. In the case reported here, a woman presented with an ectopic pregnancy after use of Levonelle-2 as postcoital contraception; there were no clinical predisposing risk factors. In the absence of any histological evidence of tubal damage, we suspect that the levonorgestrel from Levonelle-2 could have been responsible for delayed embryo transfer which resulted in the ectopic pregnancy.     

Focal fatty infiltration of the liver simulating metastatic disease

Two cases are reported in which multiple, well-defined lesions of the liver, as seen on computed tomographic (CT) scans and sonograms, were thought to represent metastatic malignancy. Results from radionuclide scans and biopsies (and surgery in one case) indicated the correct diagnosis was fatty infiltration of the liver. Focal fatty infiltration should be considered in cases of multiple discrete hepatic lesions, especially in patients with a predisposing condition. Radionuclide studies and biopsies may be needed to confirm the diagnosis by CT.     

Coping flexibility in college students with depressive symptoms

Background  

The current study explored the prevalence of depressed mood among Chinese undergraduate students and examined the coping patterns and degree of flexibility of flexibility of such patterns associated with such mood.     

Functional consequences of an arginine180 to glutamine mutation in factor IX Hilo

Factor IX Hilo is a variant factor IX molecule that has no detectable coagulant activity. The defect in factor IX Hilo arises from a point mutation in the gene such that in the protein Arg180 is converted to a Gln. Activation of factor IX Hilo by factor Xla was monitored using the fluorescent active site probe p-aminobenzamidine. Normal factor IX showed complete activation in one hour as determined by measuring the increase in fluorescence when p-aminobenzamidine bound to activated factor IX. Factor IX Hilo showed no increase in fluorescence even after 24 hours, indicating that the active site was not exposed. Polyacrylamide gel electrophoresis showed that factor IX Hilo was cleaved to a light chain plus a larger peptide with a molecular weight equivalent to a heavy chain covalently linked to an activation peptide. Amino terminal amino acid sequencing of factor IX Hilo cleaved by factor Xla showed cleavage only at Arg145-Ala146, indicating that the Gln180-Val181 bond was not cleaved and that the active site was thus not exposed. The presence of factor IX Hilo in patient plasma was responsible for the patient having a very long ox brain prothrombin time characteristic of severe hemophilia Bm. Patient plasma had an ox brain prothrombin time of 100 seconds using a Thrombotest kit, significantly prolonged over the normal control value of 45 seconds. When factor IX Hilo was depleted from patient plasma using an immunoaffinity column, the ox brain prothrombin time decreased to 41 seconds. When factor IX Hilo was added back to depleted patient plasma, to normal plasma depleted of factor IX by the same affinity column, or to plasma from a CRM- hemophilia B patient, the ox brain prothrombin time was significantly prolonged. We conclude that the Arg180 to Gln mutation in factor IX Hilo results in a molecule that cannot be activated by factor Xla. Further, our data suggest that the mutation results in a molecule that interacts with components of the extrinsic pathway to give a prolonged ox brain prothrombin time.     

EECP in the treatment of endothelial dysfunction: preventing progression of cardiovascular disease

Enhanced external counterpulsation
Extemal counterpulsation （ECP） was originally conceived to be a circulatory assist device to promote blood flow to areas of the heart muscle that were lacking adequate blood supply due to obstruction of the coronary artery. During ECP the lower extremities are compressed to squeeze both arterial and venous blood back to the heart during diastole, increasing coronary perfusion pressure and right ventricular filling. The compression is released during systole,