410 research outputs found
CT Images of a Malignant-Transformed Ovarian Mature Cystic Teratoma with Rupture: a Case Report
A malignant transformation or a tumor rupture is a rare complication of ovarian mature cystic teratoma (MCT). A tumor rupture in a malignant-transformed MCT has never been reported in the literature. We present the CT images of a 39-year-old woman showing a large, predominantly cystic mass in the lower abdomen, with fat-fluid-level ascites. A contrast-enhanced solid component, with regional discontinuity within the cystic lesion, is also demonstrated. The pathologic diagnosis of the ruptured MCT unveils the malignant transformation (squamous cell carcinoma) and mesenteric carcinomatosis
Telomere length tracking in children and their parents:Implications for adult onset diseases
Adults with comparatively short or long leukocyte telomere length (LTL) typically continue to display comparatively short or long LTL throughout life. This LTL tracking stems from the inability of person-to-person variation in age-dependent LTL shortening during adulthood to offset the wide interindividual LTL variation established prior to adult life. However, LTL tracking in children is unstudied. This study aimed to examine LTL shortening rates and tracking in children and their parents. Longitudinal study in children (n = 67) and their parents (n = 99), whose ages at baseline were 11.4 +/- 0.3 and 43.4 +/- 0.4 yr, respectively. LTL was measured by Southern blotting at baseline and similar to 14 yr thereafter. LTL displayed tracking in both children [intraclass correlation coefficient (ICC) = 0.905, P <0.001] and their parents (ICC = 0.856, P <0.001). The children's rate of LTL shortening was twice that of their parents (40.7 +/- 2.5 bp/yr; 20.3 +/- 2.1 bp/yr, respectively; P <0.0001). LTL tracking applies not only to adulthood but also to the second decade of life. Coupled with previous work showing that the interindividual variation in LTL across newborns is as wide as in their parents, these findings support the thesis that the LTL-adult disease connection is principally determined before the second decade of life, perhaps mainly at birth
Bacteremic pneumonia caused by Nocardia veterana in an HIV-infected patient
SummaryDisseminated Nocardia veterana infection has rarely been reported. We describe the first reported case of N. veterana bacteremic pneumonia in an HIV-infected patient. The isolate was confirmed by 16S rRNA sequencing analysis. The patient initially responded well to trimethoprimāsulfamethoxazole treatment (minimum inhibitory concentration 0.25Ī¼g/ml), but died of ventilator-associated pneumonia
Buildup from birth onward of short telomeres in human hematopoietic cells
Telomere length (TL) limits somatic cell replication. However, the shortest among the telomeres in each nucleus, not mean TL, is thought to induce replicative senescence. Researchers have relied on Southern blotting (SB), and techniques calibrated by SB, for precise measurements of TL in epidemiological studies. However, SB provides little information on the shortest telomeres among the 92 telomeres in the nucleus of human somatic cells. Therefore, little is known about the accumulation of short telomeres with age, or whether it limits the human lifespan. To fill this knowledge void, we used the Telomere-Shortest-Length-Assay (TeSLA), a method that tallies and measures single telomeres of all chromosomes. We charted the age-dependent buildup of short telomeres (<3ākb) in human hematopoietic cells from 334 individuals (birth-89āyears) from the general population, and 18 patients with dyskeratosis congenita-telomere biology disorders (DC/TBDs), whose hematopoietic cells have presumably reached or are close to their replicative limit. For comparison, we also measured TL with SB. We found that in hematopoietic cells, the buildup of short telomeres occurs in parallel with the shortening with age of mean TL. However, the proportion of short telomeres was lower in octogenarians from the general population than in patients with DC/TBDs. At any age, mean TL was longer and the proportion of short telomeres lower in females than in males. We conclude that though converging to the TL-mediated replicative limit, hematopoietic cell telomeres are unlikely to reach this limit during the lifespan of most contemporary humans.</p
Telomeres and replicative cellular aging of the human placenta and chorioamniotic membranes
Recent hypotheses propose that the human placenta and chorioamniotic membranes (CAMs) experience telomere length (TL)-mediated senescence. These hypotheses are based on mean TL (mTL) measurements, but replicative senescence is triggered by short and dysfunctional telomeres, not mTL. We measured short telomeres by a vanguard method, the Telomere shortest length assay, and telomere-dysfunction-induced DNA damage foci (TIF) in placentas and CAMs between 18-week gestation and at full-term. Both the placenta and CAMs showed a buildup of short telomeres and TIFs, but not shortening of mTL from 18-weeks to full-term. In the placenta, TIFs correlated with short telomeres but not mTL. CAMs of preterm birth pregnancies with intra-amniotic infection showed shorter mTL and increased proportions of short telomeres. We conclude that the placenta and probably the CAMs undergo TL-mediated replicative aging. Further research is warranted whether TL-mediated replicative aging plays a role in all preterm births
Increasing Incidence of Nontuberculous Mycobacteria, Taiwan, 2000ā2008
To assess the species distribution and epidemiologic trends of nontuberculous mycobacteria, we examined isolates from patients in Taiwan. During 2000ā2008, the proportion increased significantly from 32.3% to 49.8%. Associated disease incidence increased from 2.7 to 10.2 cases per 100,000 patients. Mycobacterium avium complex and M. abscessus were most frequently isolated
Klebsiella pneumoniae Bacteremia and Capsular Serotypes, Taiwan
Capsular serotypes of 225 Klebsiella pneumoniae isolates in Taiwan were identified by using PCR. Patients infected with K1 serotypes (41 isolates) had increased community-onset bacteremia, more nonfatal diseases and liver abscesses, lower Pittsburgh bacteremia scores and mortality rates, and fewer urinary tract infections than patients infected with nonāK1/K2 serotypes (147 isolates)
Biomechanical comparison of pedicle screw fixation strength among three different screw trajectories using single vertebrae and one-level functional spinal unit
Three key factors are responsible for the biomechanical performance of pedicle screw fixation: screw mechanical characteristics, bone quality and insertion techniques. To the best of the authorsā knowledge, no study has directly compared the biomechanical performance among three trajectories, i.e., the traditional trajectory (TT), modified trajectory (MT) and cortical bone trajectory (CBT), in a porcine model. This study compared the pullout strength and insertion torque of three trajectory methods in single vertebrae, the pullout strength and fixation stiffness including flexion, extension, and lateral bending in a one-level instrumented functional spinal unit (FSU) that mimics the in vivo configuration were clarified. A total of 18 single vertebrae and 18 FSUs were randomly assigned into three screw insertion methods (n = 6 in each trajectory group). In the TT group, the screw converged from its entry point, passed completely inside the pedicle, was parallel to the superior endplate, was located in the superior third of the vertebral body and reached to at least the anterior third of the vertebral body. In the MT group, the convergent angle was similar to that of the TT method but directed caudally to the anterior inferior margin of the vertebral body. The results of insertion torque and pullout strength in single vertebrae were analyzed; in addition, the stiffness and pullout strength in the one-level FSU were also investigated. This study demonstrated that, in single vertebrae, the insertion torque was significantly higher in CBT groups than in TT and MT groups (p < 0.05). The maximal pullout strength was significantly higher in MT groups than in TT and CBT groups (p < 0.05). There was no significant difference in stiffness in the three motions among all groups. The maximal pullout strength in FSUs of MT and CBT groups were significantly higher than the TT groups (p < 0.05). We concluded that either MT or CBT provides better biomechanical performance than TT in single vertebrae or FSUs. The lack of significance of stiffness in FSUs among three methods suggested that MT or CBT could be a reasonable alternative to TT if the traditional trajectory was not feasible
Thrombomodulin Regulates Keratinocyte Differentiation and Promotes Wound Healing
The membrane glycoprotein thrombomodulin (TM) has been implicated in keratinocyte differentiation and wound healing, but its specific function remains undetermined. The epidermis-specific TM knockout mice were generated to investigate the function of TM in these biological processes. Primary cultured keratinocytes obtained from TMlox/lox; K5-Cre mice, in which TM expression was abrogated, underwent abnormal differentiation in response to calcium induction. Poor epidermal differentiation, as evidenced by downregulation of the terminal differentiation markers loricrin and filaggrin, was observed in TMlox/lox; K5-Cre mice. Silencing TM expression in human epithelial cells impaired calcium-induced extracellular signalāregulated kinase pathway activation and subsequent keratinocyte differentiation. Compared with wild-type mice, the cell spreading area and wound closure rate were lower in keratinocytes from TMlox/lox; K5-Cre mice. In addition, the lower density of neovascularization and smaller area of hyperproliferative epithelium contributed to slower wound healing in TMlox/lox; K5-Cre mice than in wild-type mice. Local administration of recombinant TM (rTM) accelerated healing rates in the TM-null skin. These data suggest that TM has a critical role in skin differentiation and wound healing. Furthermore, rTM may hold therapeutic potential for the treatment of nonhealing chronic wounds
- ā¦