Improved control of image optical density with low-dose digital and conventional radiography in bedside imaging

The technical and diagnostic performance of simultaneously acquired low-dose (44% of standard dose) storage-phosphor digital radiographs (system resolution = 0.2 mm, 10 bits) were compared with those of standard-dose conventional bedside radiographs of the chest in 32 patients. The mean optical density (OD) of the lungs (800 measurements) was closer to the ideal density with digital radiography (1.45 OD +/- 0.20 [standard deviation] vs 1.75 OD +/- 0.53) and was less often outside the usable range (2.5% vs 42.5%). Receiver operating characteristic analysis for detection of simulated nodules and monitoring devices (nine readers, 4,608 observations) showed that digital radiography was superior to conventional radiography (P less than .05) for four of the nine readers and equivalent to conventional radiography for five readers. The authors concluded that digital radiography produces more consistent and ideal image density and performs at least as well as conventional radiography under phantom test conditions.     

应用导数光谱法考察苯呋洛尔溶液体外经皮渗透性

本文应用二阶导数紫外分光光度法考察了苯呋洛尔溶液体外经皮渗透性。考察了促进剂月桂氮(?)酮-丙二醉及PEG-400溶剂对其渗透性的影响。应用二阶导数紫外分光光度法消除了兔皮溶出物对一般紫外测定方法的干扰。结果表明:苯呋洛尔溶液具有体外经皮渗透性;月桂氮(?)酮-丙二醇系统及PEG-400均能增强苯呋洛尔溶液的体外经皮渗透性。     

Common stomal problems following ideal conduit urinary diversion. Recognition and treatment

Stomal complications following ileal conduit urinary diversion continue to be reported unduly high numbers. Some of the complications in the immediate postoperative period could be prevented by increased awareness of the importance of the type and location of the stomal bud and management of the collection device. Over the long-term, close follow-up to insure that the appliances fit properly, are kept meticulously clean, and that an acid urine is maintained will obviate any of the distressing sequelae associated with the ureteroileocutaneous anastomosis. Recognition the most common problems and suggestions for simple conservative treatment are offered.     

Iliopsoas muscles: MR study of normal anatomy and disease

Magnetic resonance (MR) imaging was performed on 15 healthy subjects to define the appearance of the iliopsoas muscle and on 15 patients with iliopsoas disease. Seven patients had tumorous involvement of the muscles, five had inflammatory disease, one had retroperitoneal hemorrhage, one had iliopsoas bursitis, and one had bilateral hypertrophy. MR imaging permitted delineation of the muscles and depiction of the disease condition. Transverse MR images alone almost always provided the necessary data to determine the origin and extent of disease. Sagittal images were occasionally useful in defining the extension of disease into the spine. T1-weighted images provided optimal contrast between the muscles and adjacent tissues, while T2-weighted images were more useful for depicting disease within the muscles themselves.     

Prevalence of <Emphasis Type="Italic">von Hippel-Lindau</Emphasis> gene mutations in sporadic renal cell carcinoma: results from the Netherlands cohort study

Background  

Biallelic von Hippel-Lindau (VHL) gene defects, a rate-limiting event in the carcinogenesis, occur in approximately 75% of sporadic clear-cell Renal Cell Carcinoma (RCC). We studied the VHL mutation status in a large population-based case group.     

Bone Mineral Density Increases in Trans Persons After 1 Year of Hormonal Treatment: A Multicenter Prospective Observational Study

Sex steroids are important determinants of bone acquisition and bone homeostasis. Cross‐sex hormonal treatment (CHT) in transgender persons can affect bone mineral density (BMD). The aim of this study was to investigate in a prospective observational multicenter study the first‐year effects of CHT on BMD in transgender persons. A total of 231 transwomen and 199 transmen were included who completed the first year of CHT. Transwomen were treated with cyproterone acetate and oral or transdermal estradiol; transmen received transdermal or intramuscular testosterone. A dual‐energy X‐ray absorptiometry (DXA) was performed to measure lumbar spine (LS), total hip (TH), and femoral neck (FN) BMD before and after 1 year of CHT. In transwomen, an increase in LS (+3.67%, 95% confidence interval [CI] 3.20 to 4.13%, p < 0.001), TH (+0.97%, 95% CI 0.62 to 1.31%, p < 0.001), and FN (+1.86%, 95% CI 1.41 to 2.31%, p < 0.001) BMD was found. In transmen, TH BMD increased after 1 year of CHT (+1.04%, 95% CI 0.64 to 1.44%, p < 0.001). No changes were observed in FN BMD (–0.46%, 95% CI –1.07 to 0.16%, p = 0.144). The increase in LS BMD was larger in transmen aged ≥50 years (+4.32%, 95% CI 2.28 to 6.36%, p = 0.001) compared with transmen aged <50 years (+0.68%, 95% CI 0.19 to 1.17%, p = 0.007). In conclusion, BMD increased in transgender persons after 1 year of CHT. In transmen of postmenopausal age, the LS BMD increased more than in younger transmen, which may lead to the hypothesis that the increase in BMD in transmen is the result of the aromatization of testosterone to estradiol. © 2017 American Society for Bone and Mineral Research.     

The variable expressivity and incomplete penetrance of the twist-null heterozygous mouse phenotype resemble those of human Saethre-Chotzen syndrome

Most targeted gene mutations are recessive and analyses of gene function often focus on homozygous mutant phenotypes. Here we describe parts of the expression pattern of M-twist in the head of developing wild-type mice and present our analysis of the phenotype of heterozygous twist- null animals at around birth and in adults. A number of twist -null heterozygous mice present skull and limb defects and, in addition, we observed other malformations, such as defects in middle ear formation and the xyphoid process. Our study is of interest to understand bone formation and the role of M-twist during this process, as within the same animal growth of some bones can be accelerated while for others it can be delayed. Moreover, we show here that expressivity of the mouse mutant heterozygous phenotype is dependent on the genetic background. This information might also be helpful for clinicians, since molecular defects affecting one allele of the human H-twist ( TWIST ) gene were identified in patients affected with Saethre-Chotzen syndrome (SCS). Expressivity of this syndrome is variable, although most patients present craniofacial and limb malformations resembling those seen in mutant mice. Thus the mutant mouse twist -null strain might be a useful animal model for SCS. The twist -null mutant mouse model, combined with other mutant mouse strains, might also help in an understanding of the etiology of morphological abnormalities that appear in human patients affected by other syndromes.      

Alterations in the Proportions of Skeletal Muscle Proteins following a Unilateral Lesion to the Substantia Nigra Pars Compacta of Rats

It is well established that mammalian skeletal muscles exhibit a considerable degree of plasticity and one of the main determining factors of this plasticity is the activity pattern and duration of motoneurone discharge. Lesions to the right substantia nigra pars compacta (SNpc) of six adult rats were made to determine whether altered output from the SNpc ultimately leads to a change in the expression of proteins in contralateral skeletal muscles. After 4 months, altered motor performance was identified by the administration of amphetamine. After 7 months, 30–70% of dopaminergic cells in the SNpc had been destroyed. The protein content of muscles was then quantified from densitometric scans of gels, and expressed as a % of the amount of actin (the protein used as a reference in this study). The lesion affected the expression of different protein isoforms in the fast- and slow-twitch muscles. In slow-twitch soleus muscles, the lesion decreased the proportion of α-tropomyosin and increased the proportion of β-tropomyosin. In the fast-twitch extensor digitorum longus muscles, the lesion increased the proportion of the fast isoform of troponin-T_1f, and decreased the proportions of the two isoforms of myosin light chain. This study establishes a connection between the chronic effects of a lesion to the SNpc, with a loss of dopaminergic neurones, impaired motor performance, and altered expression of proteins in skeletal muscle. The implication of these results is that the altered motor function observed in Parkinson’s disease may be associated with alterations to the expression of skeletal muscle proteins. Supported by grants from NH & MRC (DF) and Faculty of Health Sciences, LaTrobe University (PD).     

Alzheimer's disease associated with mutations in presenilin 2 is rare and variably penetrant

Missense mutations in the presenilin 2 (PS-2) gene on chromosome 1 were sought by direct nucleotide sequence analysis of the open reading frame of 60 pedigrees with familial Alzheimer's disease (FAD). In the majority of these pedigrees, PS-1 and beta-amyloid precursor protein (beta APP) gene mutations had been excluded. While no additional PS-2 pathogenic mutations were detected, four silent nucleotide substitutions and alternative splicing of nucleotides 1338-1340 (Glu325) were observed. Analysis of additional members of a pedigree known to segregate a Met239Val mutation in PS-2 revealed that the age of onset of symptoms is highly variable (range 45-88 years). This variability is not attributable to differences in ApoE genotypes. These results suggest (i) that, in contrast to mutations in PS-1, mutations in PS-2 are a relatively rare cause of FAD; (ii) that other genetic or environmental factor modify the AD phenotype associated with PS-2 mutations; and (iii) that still other FAD susceptibility genes remain to be identified.