Early-senescing human skin fibroblasts do not demonstrate accelerated telomere shortening

Most normal mammalian cell lines demonstrate limited growth capacity due to the gradual accumulation of senescent cells in the culture. Senescent cells appear initially at a low incidence, but with increasing frequency as the culture accumulates more divisions. Because it has been suggested that senescence is regulated by telomere shortening in human cells, we compared the telomere lengths of the subpopulation of senescent cells, present in presenescent cultures, with those of young cells. Senescent cells were separated from young cycling cells by either bromodeoxyuridine (BrdU) incorporation followed by Hoechst dye and light treatment or DiI staining followed by separation on a high-speed cell sorter. Our results demonstrate that telomeres of early-senescing cells are the same length, and must shorten at the same rate, as cycling sister cells in the culture. Therefore, senescent cells in young mass cultures occur as a result of a stochastic, nontelomere-dependent process that we have described: sudden senescence syndrome.     

Structural, immunocytochemical, and mr imaging properties of periventricular crossroads of growing cortical pathways in preterm infants

BACKGROUND AND PURPOSE: Periventricular white matter (WM) areas are widely recognized as predilection sites for complex cellular damage after ischemia/reperfusion or inflammatory injury of the perinatal cerebrum. We analyzed histochemical and MR imaging properties of fiber architectonics and extracellular matrix (ECM) of periventricular areas to disclose the potential significance of topographically specific WM lesions for the neurodevelopmental outcome. METHODS: We combined histochemical methods for demonstration of fibers, axonal guidance molecules, and ECM with T1-weighted MR images on postmortem specimens aged 15 to 36 postovulatory weeks (POW) and T2-weighted MR images on in vivo fetuses aged 14 to 26 POW. RESULTS: The fiber architectonics of the fetal cerebrum display tangential axon strata in frontopolar and occipitopolar regions, whereas the central periventricular region contains crossroads of intersecting callosal (transverse), associative (sagittal), and thalamocortical/corticofugal (radial) fiber bundles. In early preterms, crossroads contain hydrophylic ECM with axonal guidance molecules, and they are easily recognized as hypointensities on T1-weighted MR images or hyperintensities on T2-weighted MR images. After the 28 POW, tangential fetal fiber-architectonic stratification transforms into the corona radiata system; however, the growth of cortical pathways continues in crossroad areas, as indicated by the presence of ECM and their distinct MR imaging signal intensities. CONCLUSIONS: The correlation of MR imaging with histochemical findings demonstrated the presence of periventricular fiber crossroads rich in ECM and axonal guidance molecules. We propose that, in perinatal WM lesions, periventricular WM crossroads represent a hitherto unrecognized and vulnerable cellular and topographic target in which combined damage of association-commissural and projection fibers may explain the complexity of cognitive, sensory, and motor deficit in survivors of periventricular WM lesions.     

Relationship between loss of pedal sensibility, balance, and falls in patients with peripheral neuropathy

: The purpose of this study was to describe the relationship between balance and foot sensibility in a population of patients with impaired lower extremity sensation. The hypothesis was that increasing impairment of sensation correlates with impaired balance. To date, no report has investigated the relationship between loss of balance with the degree of sensibility in the foot in a population with neuropathy. Ten control subjects and 35 patients with sensory abnormalities and balance problems related to a neuropathy were evaluated. The MatScan Measurement System was used to measure their ability to stand still, maintaining their balance with their eyes open and then with their eyes shut. The degree to which the person moves while attempting to stand still is defined as "sway," which was recorded for normal and neuropathy patients. Sensibility of the foot was measured with the Pressure-Specified Sensory Device, which is noninvasive and nonpainful. The 1- and 2-point static touch thresholds are measured for the pulp of the big toe, medial heel, and the dorsum of the foot. Loss of 2- or 1-point sensation was recorded as sensibility score and compared with controls. Statistical analysis of data and their comparisons for the 2 groups was completed. There were 55% females in control and 64% in neuropathy patients, whereas average age was 50 and 62 years, respectively. Neuropathy was the result of diabetes in 64.5%, hypothyroidism in 19.3%, their combination in 13%, and of unknown etiology in the remaining 19% of patients. Controls had significantly lower mean sway than neuropathy patients (22.9 +/- 9% vs. 189.5 +/- 180%, P = 0.006). Likewise, sensibility score for normal and neuropathy patients was also significantly different (31.4 +/- 9% vs. 232.8 +/- 59%, P <0.0001). When compared with the controls, 99% upper limit of confidence, sensibility in the neuropathy group at the hallux pulp was abnormal at a level consistent with axonal loss in 52% and was completely absent in the remaining 48%. Similarly, at the heel, sensibility was normal in 6.5%, abnormal at a level consistent with axonal loss in 71%, and absent in the remaining 22.5%. The correlation coefficient between sway and sensibility score was 0.36. The results of this investigation for the first time document the intuitive relationship between increasing loss of foot sensibility and increasing loss of balance. These measurements can now be used prospectively to evaluate whether restoration of sensation to patients with neuropathy, through peripheral nerve decompression, can improve balance and reduce falls/fractures in this patient population.     

Changes in dentin after insertion of self-threading titanium pins with 3 methods: a scanning electron microscope pilot study

STATEMENT OF PROBLEM: Inserting a self-threading pin can cause dentinal cracks, but it is not known whether dentin bonding agents can penetrate these cracks. PURPOSE: Part I of this in vitro pilot study was conducted to document the presence of dentinal cracks after the placement of self-threading pins with 3 methods. Part II was conducted to observe changes in dentin when a dentin bonding agent was applied before insertion of the self-threading pins. MATERIAL AND METHODS: The crowns of 14 noncarious third molars were sectioned horizontally 2 mm above the cemento-enamel junction, and the occlusal portions were discarded. The teeth were put into a nontransparent bag and divided randomly into 2 groups. Group 1 consisted of 12 teeth. In each tooth, 4 pinholes were prepared with a handpiece at normal rotation speed (30,000 rpm). Self-threading pins were placed into 3 of the pinholes in each tooth: 1 manually, 1 by handpiece at 7000 rpm, and 1 by handpiece at 30,000 rpm. The fourth pinhole was left empty and served as the control. All group 1 teeth were sectioned vertically through the pins, dental hard tissue, and control pin holes. The examination surface of each specimen in group 1 was polished, and the smear layer was removed with Calcinase and NaOCl solutions. After dehydration in ascending grades of alcohol, specimens were coated with a 10- to 15-nm-thick layer of gold and examined with a scanning electron microscope. In the remaining 2 teeth (group 2), a dentin bonding agent was introduced into the pinholes prior to pin placement. Two pins were placed manually and 2 by handpiece at 30,000 rpm. After pin placement, sectioning, cleaning, and dehydration, the specimens were examined with a scanning electron microscope, and x-ray mapping was performed to determine the presence of titanium, silicon, and calcium. RESULTS: Craze lines in dentin were associated with 54.5% of pins placed manually and 54.5% of pins placed with a handpiece at reduced speed (7000 rpm). Dentinal cracks were associated with 50% of pins placed with a handpiece at standard speed and with 16.7% of the control pinholes. X-ray mapping analysis revealed the presence of the dentin bonding agent between the pin and dentin wall. The dentin bonding agent was not found in the dentinal cracks except at the crack orifice. SUMMARY: Within the limitations of this pilot study, the method of pin insertion had no direct bearing on the presence of dentinal cracks. The dentin bonding agent tested did not fill the entire space of dentinal cracks but did occlude their orifices and fill the spaces between pin surface and dentin walls in the pin preparation.     

Crosslinked polyethylene/polypropene blends, 1. Formation of insoluble parts,crystallization and melting

Crosslinked blends of low density polyethylene/isotactic polypropene (LDPE/iPP) were studied over the whole composition range. The degree of crosslinking was determined from the gel content and the degree of swelling. In the presence of a coagent an efficient crosslinking of polypropene can be observed in blends whereas in the absence of the coagent only the PE component is crosslinked. Thermal characterization of the blends by differential scanning calorimetry (DSC), i.e. heat of fusion, melting and crystallization temperatures suggest that the crosslinking results in the formation of a structure with molecules of both components being mutually connected. A two-phase structure is still maintained and crosslinked molecules of polypropene (PP) and polyethylene (PE) are found at the interface. The effect of crosslinking on the rate of crystallization is different for PE and PP. This phenomenon is explained by the superposition of the influence of crosslinking on the rate of crystal growth and nucleation.     

Hospital information system--project of implementation of SAP information system at Sveti Duh General Hospital

Nowadays, as medical and hospital institutions have been facing a growing need of a more efficient provision of healthcare services to patients, with simultaneous complete monitoring of the successfulness of business activities, integrated information systems appear as the logical choice for the support to hospital business processes. The integrated business information system implemented at Sveti Duh General Hospital is a comprehensive system that supports all hospital, clinical and administrative processes, while providing the basis for decision making regarding the patients and hospital management. The system also enables transfer of all data with specific medical business segments such as laboratory device management. The project for the implementation of the information system was realized in accordance with the requests from the Ministry of Health, applying the proven methodology for the execution of such complex projects. The project team consisted of a number of consultants from b4b Co. from Zagreb, as well as Hospital employees. The new information system is completely ready for going live; however, the necessary decisions have to be made first. The application of the system gives the medical staff more time for their professional work with patients, and through longterm collection and analysis of data on symptoms, illnesses and medical treatments, the information system becomes an important tool for the improvement of health and quality of healthcare system in general.     

No adverse effect of ABVD chemotherapy in a patient with chronic hepatitis C and Hodgkin’s disease

There is insufficient information on the effects of chemotherapy protocols for Hodgkin's disease (HD) and the course of coexisting hepatitis C virus (HCV) infection. A single literature case reported a patient with HD who developed fulminant hepatitis and hepatic coma after receiving chemotherapy. The case described here is of a female patient previously exposed to prolonged war stress, complicated by intravenous drug abuse and chronic hepatitis C. One year after diagnosis of HCV infection she was diagnosed with HD (nodular sclerosis type II, clinical stage IIIB). The patient received six cycles of ABVD chemotherapy (doxorubicin, bleomycin, vinblastine and dacarbazine) resulting in complete remission of HD. There was no hepatitis flare either during or after chemotherapy. In conclusion, there were no adverse effects of the ABVD regimen on the course of HCV infection in this patient who was successfully treated for HD. Because concurrent HCV infection and HD is extremely rare, we discuss here the possibility of the synergistic contribution of chronic war stress and hepatitis C infection in the pathogenesis of HD.     

Infestation of the human kidney with Dioctophyma renale

Human infestation with Dioctophyma renale is presented. Clinical signs and diagnostic findings are unspecific. They are discussed and a conservative therapeutic approach is suggested.     

Hierarchical and Redundant Lymphocyte Subset Control Precludes Cytomegalovirus Replication during Latent Infection

Reactivation from latent cytomegalovirus (CMV) infection is often associated with conditions of immunosuppression and can result in fatal disease. Whether the maintenance of systemic CMV latency is mainly governed by factors of the infected cell or by immune control functions is unknown. Likewise, the putative immune control mechanisms which could prevent the induction and spread of recurrent CMV infection are not clearly identified. We took advantage of latently infected B cell–deficient mice and a sensitive method for virus detection to study CMV reactivation after ablation of lymphocyte subsets. A crucial role of both T lymphocytes and natural killer (NK) cells was demonstrated. Within 5 d after depletion of lymphocytes, productive infection occurred in 50% of mice, and 14 d later 100% of mice exhibited recurrent infection. A hierarchy of immune control functions of CD8⁺, NK, and CD4⁺ cells was established. Reactivation was rare if only one of the lymphocyte subsets was depleted, but was evident after removal of a further subset, indicating a functional redundancy of control mechanisms. The salivary glands were identified as the site of most rapid virus shedding, followed by the detection of recurrent virus in the lungs, and eventually in the spleen. Our findings document a previously unknown propensity of latent CMV genomes to enter productive infection immediately and with a high frequency after immune cell depletion. The data indicate that only the sustained cellular immune control prevents CMV replication and restricts the viral genome to a systemic state of latency.     

Laminar organization of the human fetal cerebrum revealed by histochemical markers and magnetic resonance imaging

The developing human cerebrum displays age-specific changes in its patterns of lamination. Among these, the subplate zone is the most prominent transient compartment because growing major afferent systems temporarily reside in this zone, establish synapses and take part in cellular interactions that are crucial for subsequent cortical development. We explored the potential of magnetic resonance imaging (MRI) for tracing the developmental history of the most prominent cortical layer (the subplate zone) and other laminar compartments of the fetal cerebral wall between 15 and 36 weeks post-ovulation. We found that changes in the MRI lamination pattern of the human fetal cerebral wall are predominantly caused by changes in the subplate zone. Histochemical staining of the extracellular matrix (ECM) enables selective visualization of the subplate zone and correlation with an increase in MRI signal intensity in the subplate zone and ingrowth and accumulation of thalamocortical and corticocortical afferents and their subsequent relocation to the cortical plate. Thus, dynamic changes in the MRI appearance of the subplate zone and histochemical staining of its ECM can be used as indirect parameters for an assessment of normal versus disturbed unfolding of crucial histogenetic events that are involved in prenatal shaping of the human cerebral cortex.