Probable implication of mutations of the X open reading frame in the onset of fulminant hepatitis B

A pathogenic role of precore-defective mutation in the onset of fulminant hepatitis B has been suggested. However, precore-defective mutants do not always cause fulminant hepatitis B and are not always isolated from affected patients. These findings strongly suggest the presence of some additional important mutations outside the precore region in fulminant hepatitis. In the present investigation an attempt was made to sequence the X open reading frame of hepatitis B virus DNA isolated from seven patients with fulminant hepatitis B and five patients with acute hepatitis B. The latter were used as controls. Since the X open reading frame encodes the X protein and contains the core promoter/enhancer II complex, some critical mutations may enhance or disrupt the replication and expression of hepatitis B virus DNA leading to fulminant hepatitis. A C-to-T substitution was found at nucleotide (nt) 1655, an A-to-T substitution at nt 1764 and a G-to-A substitution at nt 1766 in 4, 5 and 5 patients, respectively, out of the seven with fulminant hepatitis. These substitutions were not recognized in the patients with acute hepatitis. These mutations might change the function of the X protein and core promoter/enhancer II complex. It is suggested, therefore, that these mutations, as well as the precore-defective mutation, may play an important role in the pathogenesis of fulminant hepatitis. © Wiley-Liss, Inc.     

Removal Tools are Faster and Produce Less Force and Torque on the Helmet Than Cutting Tools During Face-Mask Retraction

OBJECTIVE: To investigate the retraction time, forces, and torques applied to the football helmet during removal of the face mask with different face-mask removal tools. DESIGN AND SETTING: Subjects retracted the face mask of a football helmet mounted to a force platform in a laboratory setting. They removed a standard face mask by cutting or removing (or both) the lateral plastic loop straps using 4 different tools: the Trainer's Angel (TA), FM Extractor (FM), power screwdriver (SD), and Quick Release System (QR) in a counterbalanced fashion. SUBJECTS: Eighteen certified athletic trainers participated in this study. MEASUREMENTS: We started measuring time when the subject picked up the tool and ended when the face mask was in a fully retracted position. Maximum forces and torques were measured from the force platform during the retraction process. RESULTS: The SD and QR retracted the face mask significantly faster than the TA and FM. Forces producing superior-inferior translation were least with the SD. The SD and QR produced less lateral translation and rotation and lateral flexion moment than the TA and FM. The FM produced less torque in the lateral flexion moment than the TA. CONCLUSIONS: Tools that removed the loop straps (SD, QR) were faster and produced less force and torque on the helmet than the tools that cut through the loop straps (TA, FM).     

Argyrophilic nucleolar organizer regions in colorectal malignancy: application of typing by their density

Colorectal neoplasms obtained at colonoscopy were examined by argyrophilic nucleolar organizer region (AgNOR) staining to evaluate the usefulness of AgNOR as a discriminant for malignancy. AgNOR dots were divided into two kinds: 'structures' (larger and less-densely stained) corresponding to the nucleolus, and 'units' (smaller and densely stained) presumed to be true AgNOR within the structure. The number of structures per nucleus did not differ between the adenoma and carcinoma groups, whereas the number of units per nucleus showed a significant difference. However there were several cases showing an overlap between the adenoma and carcinoma groups, leading to a difficulty in deciding whether any given case was benign or malignant. Three types of AgNOR patterns were categorized based on the ratio of units to structure. Type I was defined as the unit being indistinguishable from the structure, Type II as each structure having one to five units, and Type III as at least one structure having six or more units, irrespective of total number of units per nucleus. The colorectal lesions in which more than half of the neoplastic cells showed Type III coincided well with carcinomas histologically diagnosed, with the exception of adenomas with severe atypia. Labeling index of proliferating cell nuclear antigen (PCNA LI) differed between the adenoma and carcinoma groups with a considerable extent of overlap, and correlated to some extent with the AgNOR values. These results showed that the AgNOR staining was useful for determining malignancy and its usefulness appeared superior to PCNA LI.     

Supradiaphragmatic ectopic adrenocorticotropic hormone-secreting adenoma

A 22-year-old woman with Cushing's syndrome, caused by an extremely rare suprasellar ectopic pituitary adenoma, is presented. Magnetic resonance imaging and computed tomography revealed a well-circumscribed mass in the right suprasellar region. Endocrinological tests showed elevated s-adrenocorticotropic hormone level and hypercortisolemia. The tumor was totally removed by right subfrontal approach. At the time of the operation, the tumor was in continuity with the distal pituitary stalk but not with the pituitary gland. The diaphragma sellae was intact. Histologic diagnosis of the tumor specimen was confirmed as a pituitary adenoma. After surgical removal of the tumor, continued improvement in the patient's laboratory results and disappearance of her endocrine symptoms strongly indicated the absence of adenoma cells in the pituitary gland or stalk. Six years post-surgery, there was no evidence of recurrence in the patient's clinical and laboratory examination. This tumor probably originated from aberrant anterior pituitary cells of the pituitary stalk.     

面神经颞支的应用解剖学研究

目的:为预防额颞区手术和翼点入路的颅内手术损伤面神经颞支提供解剖学资料。方法:60侧成人头部标本,解剖观测面神经颞支的分支、行程及层次。结果:(1)面神经颞支多为2~4支,占95.00％(57侧)。(2)面神经颞支离开腮腺上缘后向前上走行,从颧弓浅面跨过进入额颞区,后走行于浅筋膜和颞筋膜浅层之间;在腮腺上缘及颧弓上缘处面神经颞支的最后1支距耳屏尖的距离分别为(23.79±0.27)mm和(30.67±0.37)mm。结论:面神经颞支入肌前在颧弓以下一段位置较深、以上表浅。从耳屏尖向前23mm范围内无该神经通过,为手术安全区。     

Distribution of TT virus (TTV), TTV-like minivirus,and related viruses in humans and nonhuman primates

TT virus (TTV) and TTV-like minivirus (TLMV) are small DNA viruses with single-stranded, closed circular, antisense genomes infecting man. Despite their extreme sequence heterogeneity (>50%), a highly conserved region in the untranslated region (UTR) allows both viruses to be amplified by polymerase chain reaction (PCR). TTV/TLMV infection was detected in 88 of 100 human plasma samples; amplified sequences were differentiated into TTV and TLMV by analysis of melting profiles, showing that both viruses were similarly prevalent. PCR with UTR primers also detected frequent infection with TTV/TLMV-related viruses in a wide range of apes (chimpanzees, gorillas, orangutans, gibbons) and African monkey species (mangabeys, drills, mandrills). These findings support the hypothesis for the co-evolution of TTV-like viruses with their hosts over the period of primate speciation, potentially analogous to the evolution of primate herpesviruses.     

Heterogeneity in intergenic regions of the ribosomal repeat of the pine-blister rustsCronartium flaccidum andPeridermium pini

Mixed aeciospore isolates ofCronartium flaccidum andPeridermium pini were obtained from single-tree infections in Britain, Italy and Greece. The 5.8s ribosomal RNA gene and flanking intergenic transcribed spacer regions ITS 1 and ITS2 were found to be highly similar betweenC. flaccidum andP. pini. Within samples heterogeneity was detected at three nucleotide loci in the ITS1 and at four loci in the ITS2 suggesting that several fungal genotypes may occur at a single infection court. The heterogeneity was confirmed by heteroduplex polymorphism analysis of mixed aeciospore products. RFLP of the ribosomal intergenic spacer region 1 (IGSI) amplified from the same templates indicated limited sequence polymorphism in some copies of this repeated locus. Both the sexual and asexual forms ofC. flaccidum show evidence of sequence polymorphism in two independent, non-coding regions of the ribosomal gene array. Variation appears to be greater in the sexual formC. flaccidum, than in the monoaecious formP. pini.     

A region of heterogeneity adjacent to the 5s ribosomal RNA gene of cereal rusts

Summary Total genomic DNA was isolated from three cereal stem rusts, Puccinia graminis f. sp. tritici, f. sp. secalis, f. sp. avenae, and two cereal leaf rusts, P. recondita f. sp. tritici and P. coronata f. sp. avenae, and analyzed for the presence of heterogeneity in the intergenic region of the ribosomal DNA repeat unit. A 1 kb region of the repeat unit between the 26s and the 5s rRNA genes (IGR-1) was amplified by PCR and was found to be heterogeneous within each isolate and variable in size between races and species. The PCR results were confirmed by Southern blot analysis of native DNA. In an isolate of race C36(48), heterogeneity appeared to be due to variable numbers of 0.1 kb subrepeats in IGR-1. Nine wheat stem rust strains representing nine different races produced a unique pattern of heterogeneity while two different isolates of one race were identical, as were five of another. This may provide a rapid method for race identification in wheat stem rust. Heterogeneity and polymorphism in rye stem rust, oat stem rust, wheat leaf rust, and oat crown rust, was less pronounced than in wheat stem rust. In the course of this work, the 5s rRNA gene was located and its position and orientation within the ribosomal repeat unit was established.     

Abnormal extrapelvic course of the inferior gluteal artery

At its extrapelvic course the inferior gluteal a. is found to be strictly related to the sciatic n. This relationship has been described in a general way, emphasizing its medial localization in respect to the nerve. Clinicosurgical reports describe cases of aneurysms of the inferior gluteal a. on its extrapelvic course and subsequent compression at the nerve. In order to get further details on the relationship between these two structures, 80 gluteal regions from 40 cadavers of adult Brazilian individuals, 29 males and 11 females, were dissected. The inferior gluteal a. was found medial to the sciatic n. in 62 cases (77.5%); in the 18 remaining (22.5%) the trunk of the artery or one of its branches perforated the nerve. Of these, 14 (77.8%) were males and 4 (22.2%) females. This disposition was found 8 times (44.4%) on the right and 10 (55.6%) on the left side; was unilateral in 4 individuals (1 on the right and 3 on the left side) and bilateral in 7. The course of the inferior gluteal a. through the sciatic n. and/or the presence of aneurysms of this artery should be considered as a possible cause of nerve compression.